xtd::forms::combo_box Class Reference

Inheritance diagram for xtd::forms::combo_box:

Definition

Represents a Windows combo box control.

Header

#include <xtd/forms/combo_box>

Namespace

xtd::forms

Library

xtd.forms

Remarks

A combo_box displays a text box combined with a list_box, which enables the user to select items from the list or enter a new value.

The drop_down_style property specifies whether the list is always displayed or whether the list is displayed in a drop-down. The drop_down_style property also specifies whether the text portion can be edited. See combo_box_style for the available settings and their effects. There is no setting to always display the list and disallow entering a new value. To display a list to which no new values can be added, use a list_box control.

To add or remove objects in the list at run time, use methods of the combo_box.object_collection class (through the items property of the combo_box). You can assign an array of object with the push_range method. The list then displays the default string value for each object. You can add individual objects with the push method. You can delete items with the erase method or clear the entire list with the clear method.

In addition to display and selection functionality, the combo_box also provides features that enable you to efficiently add items to the combo_box and to find text within the items of the list. With the begin_update and end_update methods, you can add a large number of items to the combo_box without the control being repainted each time an item is added to the list. The find_string and find_string_exact methods enable you to search for an item in the list that contains a specific search string.

You can use these properties to manage the currently selected item in the list, the text property to specify the string displayed in the editing field, the selected_index property to get or set the current item, and the selected_item property to get or set a reference to the object.

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Examples

The following code example demonstrates the use of combo box control.

#include <xtd/forms/application>
#include <xtd/forms/combo_box>
#include <xtd/forms/form>
 
using namespace xtd;
using namespace xtd::drawing;
using namespace xtd::forms;
 
namespace combo_box_example {
  class form1 : public form {
  public:
    form1() {
      controls().push_back_range({combo_box1, combo_box2, combo_box3});
      text("Combo box example");
      
      combo_box1.location({10, 10});
      combo_box1.items().push_back_range({"Item1", "Item2", "Item3", "Item4", "Item5", "Item6", "Item7", "Item8", "Item9", "Item10"});
      combo_box1.selected_index(0);
      combo_box1.selected_index_changed += event_handler(*this, &form1::on_combo_box_selected_index_changed);
      
      combo_box2.location({10, 50});
      combo_box2.drop_down_style(combo_box_style::drop_down_list);
      combo_box2.items().push_back_range({"Item1", "Item2", "Item3", "Item4", "Item5", "Item6", "Item7", "Item8", "Item9", "Item10"});
      combo_box2.selected_index(0);
      combo_box2.selected_index_changed += event_handler(*this, &form1::on_combo_box_selected_index_changed);
      
      combo_box3.location({10, 90});
      combo_box3.drop_down_style(combo_box_style::simple);
      combo_box3.items().push_back_range({"Item1", "Item2", "Item3", "Item4", "Item5", "Item6", "Item7", "Item8", "Item9", "Item10"});
      combo_box3.selected_index(0);
      combo_box3.selected_index_changed += event_handler(*this, &form1::on_combo_box_selected_index_changed);
    }
    
  private:
    void on_combo_box_selected_index_changed(object& sender, const xtd::event_args& e) {
      combo_box1.selected_index(as<combo_box&>(sender).selected_index());
      combo_box2.selected_index(as<combo_box&>(sender).selected_index());
      combo_box3.selected_index(as<combo_box&>(sender).selected_index());
    }
    combo_box combo_box1;
    combo_box combo_box2;
    combo_box combo_box3;
  };
}
 
auto main() -> int {
  application::run(combo_box_example::form1 {});
}

Examples

application_enable_dark_mode.cpp, application_enable_light_mode.cpp, combo_box.cpp, demo.cpp, some_controls.cpp, some_system_controls.cpp, and themes.cpp.

Public Events
event< combo_box, event_handler >	drop_down
	Occurs when the drop-down portion of a xtd::forms::combo_box is shown.
event< combo_box, event_handler >	drop_down_closed
	Occurs when the drop-down portion of the xtd::forms::combo_box is no longer visible.
event< combo_box, event_handler >	drop_down_style_changed
	Occurs when the drop_down_style property has changed.

Public Constructors
	combo_box ()
	Initializes a new instance of the combo_box class.

Porperties
bool	dropped_down () const noexcept
	Gets a value indicating whether the combo box is displaying its drop-down portion.
combo_box &	dropped_down (bool value)
	Sets a value indicating whether the combo box is displaying its drop-down portion.
combo_box_style	drop_down_style () const noexcept
	Gets a value specifying the style of the combo box.
combo_box &	drop_down_style (combo_box_style drop_down_style)
	Sets a value specifying the style of the combo box.
object_collection &	items () noexcept
	Gets an object representing the collection of the items contained in this combo_box. Gets an object representing the collection of the items contained in this combo_box.
const object_collection &	items () const noexcept
	Gets an object representing the collection of the items contained in this combo_box. Gets an object representing the collection of the items contained in this combo_box.
const combo_box &	items (const object_collection &items)
	Sets an object representing the collection of the items contained in this combo_box. Gets an object representing the collection of the items contained in this combo_box.
list_control &	selected_index (size_t selected_index) override
	When overridden in a derived class, Sets the zero-based index of the currently selected item.
const item &	selected_item () const noexcept
	Gets currently selected item in the combo_box.
combo_box &	selected_item (const item &selected_item)
	Sets currently selected item in the combo_box.
virtual bool	sorted () const noexcept
	Gets a value indicating whether the items in the combo_box are sorted alphabetically.
virtual combo_box &	sorted (bool sorted)
	Sets a value indicating whether the items in the combo_box are sorted alphabetically.
control &	text (const xtd::string &text) override
	Sets the text associated with this control.
virtual size_t	selected_index () const noexcept
	Gets the zero-based index of the currently selected item.
virtual list_control &	selected_index (size_t selected_index)=0
	When overridden in a derived class, Sets the zero-based index of the currently selected item.

Public Methods
void	begin_update ()
	Maintains performance while items are added to the combo_box one at a time by preventing the control from drawing until the EndUpdate() method is called.
void	end_update ()
	Resumes painting the combo_box control after painting is suspended by the begin_update method.

Public Static Methods
static combo_box	create ()
	A factory to create an xtd::forms::combo_box.
static combo_box	create (const drawing::point &location)
	A factory to create an xtd::forms::combo_box with specified location.
static combo_box	create (const drawing::point &location, const drawing::size &size)
	A factory to create an xtd::forms::combo_box with specified location, and size.
static combo_box	create (const drawing::point &location, const drawing::size &size, const xtd::string &name)
	A factory to create an xtd::forms::combo_box with specified location, size, and name.
static combo_box	create (const object_collection &items)
	A factory to create an xtd::forms::combo_box with specified items.
static combo_box	create (const object_collection &items, const drawing::point &location)
	A factory to create an xtd::forms::combo_box with specified items, and location.
static combo_box	create (const object_collection &items, const drawing::point &location, const drawing::size &size)
	A factory to create an xtd::forms::combo_box with specified items, location, and size.
static combo_box	create (const object_collection &items, const drawing::point &location, const drawing::size &size, const xtd::string &name)
	A factory to create an xtd::forms::combo_box with specified items, location, size, and name.
static combo_box	create (const object_collection &items, size_t selected_index)
	A factory to create an xtd::forms::combo_box with specified items, and selected_index.
static combo_box	create (const object_collection &items, size_t selected_index, const drawing::point &location)
	A factory to create an xtd::forms::combo_box with specified items, selected_index, and location.
static combo_box	create (const object_collection &items, size_t selected_index, const drawing::point &location, const drawing::size &size)
	A factory to create an xtd::forms::combo_box with specified items, selected_index, location, and size.
static combo_box	create (const object_collection &items, size_t selected_index, const drawing::point &location, const drawing::size &size, const xtd::string &name)
	A factory to create an xtd::forms::combo_box with specified items, selected_index, location, size, and name.
static combo_box	create (const control &parent)
	A factory to create an xtd::forms::combo_box with specified parent.
static combo_box	create (const control &parent, const drawing::point &location)
	A factory to create an xtd::forms::combo_box with specified parent, and location.
static combo_box	create (const control &parent, const drawing::point &location, const drawing::size &size)
	A factory to create an xtd::forms::combo_box with specified parent, location, and size.
static combo_box	create (const control &parent, const drawing::point &location, const drawing::size &size, const xtd::string &name)
	A factory to create an xtd::forms::combo_box with specified parent, location, size, and name.
static combo_box	create (const control &parent, const object_collection &items)
	A factory to create an xtd::forms::combo_box with specified parent, and items.
static combo_box	create (const control &parent, const object_collection &items, const drawing::point &location)
	A factory to create an xtd::forms::combo_box with specified parent, items, and location.
static combo_box	create (const control &parent, const object_collection &items, const drawing::point &location, const drawing::size &size)
	A factory to create an xtd::forms::combo_box with specified parent, items, location, and size.
static combo_box	create (const control &parent, const object_collection &items, const drawing::point &location, const drawing::size &size, const xtd::string &name)
	A factory to create an xtd::forms::combo_box with specified parent, items, location, size, and name.
static combo_box	create (const control &parent, const object_collection &items, size_t selected_index)
	A factory to create an xtd::forms::combo_box with specified parent, items, and selected_index.
static combo_box	create (const control &parent, const object_collection &items, size_t selected_index, const drawing::point &location)
	A factory to create an xtd::forms::combo_box with specified parent, items, selected_index, and location.
static combo_box	create (const control &parent, const object_collection &items, size_t selected_index, const drawing::point &location, const drawing::size &size)
	A factory to create an xtd::forms::combo_box with specified parent, items, selected_index, location, and size.
static combo_box	create (const control &parent, const object_collection &items, size_t selected_index, const drawing::point &location, const drawing::size &size, const xtd::string &name)
	A factory to create an xtd::forms::combo_box with specified parent, items, selected_index, location, size, and name.

Protected Properties
forms::create_params	create_params () const noexcept override
	Gets the required creation parameters when the control handle is created.

Protected Methods
xtd::uptr< xtd::object >	clone () const override
	Creates a new object that is a copy of the current instance.
virtual void	on_drop_down (const event_args &e)
	Raises the xtd::forms::combo_box::drop_down event.
virtual void	on_drop_down_closed (const event_args &e)
	Raises the xtd::forms::combo_box::drop_down_closed event.
virtual void	on_drop_down_style_changed (const event_args &e)
	Raises the xtd::forms::combo_box::drop_down_style_changed event.
void	on_handle_created (const event_args &e) override
	Raises the xtd::forms::control::handle_created event.
void	on_selected_value_changed (const event_args &e) override
	Raises the list_control::selected_value_changed event.
void	wnd_proc (message &message) override
	Processes Windows messages.

Additional Inherited Members
Public Types inherited from xtd::forms::list_control
using	object_collection = layout::arranged_element_collection< item, item::sorter >
	Represents the collection of items in a list_control.
Public Types inherited from xtd::forms::control
using	context_menu_ref = std::reference_wrapper< xtd::forms::context_menu >
	Represent an xtd::forms::context_menu reference.
Public Attributes inherited from xtd::forms::list_control
event< list_control, event_handler >	selected_index_changed
	Occurs when the selected_index property changes.
event< list_control, event_handler >	selected_value_changed
	Occurs when the selected_value property changes.
Public Attributes inherited from xtd::forms::control
event< control, event_handler >	auto_size_changed
	Occurs when the value of the xtd::forms::control::auto_size property changes.
event< control, event_handler >	back_color_changed
	Occurs when the value of the xtd::forms::control::back_color property changes.
event< control, event_handler >	background_image_changed
	Occurs when the value of the xtd::forms::control::background_image property changes.
event< control, event_handler >	background_image_layout_changed
	Occurs when the value of the xtd::forms::control::background_image_layout property changes.
event< control, event_handler >	control_appearance_changed
	Occurs when the value of the xtd::forms::control::control_appearance property changes.
event< control, event_handler >	click
	Occurs when the xtd::forms::control is clicked.
event< control, event_handler >	client_size_changed
	Occurs when the value of the xtd::forms::control::client_size property changes.
event< control, event_handler >	cursor_changed
	Occurs when the value of the xtd::forms::control::cursor property changes.
event< control, control_event_handler >	control_added
	Occurs when a new xtd::forms::control::control is added to the xtd::forms::control::control_collection.
event< control, control_event_handler >	control_removed
	Occurs when a new xtd::forms::control:: is removed to the xtd::forms::control::control_collection.
event< control, event_handler >	dock_changed
	Occurs when the value of the xtd::forms::control::dock property changes.
event< control, event_handler >	double_click
	Occurs when the xtd::forms::control is double-clicked.
event< control, event_handler >	got_focus
	Occurs when the xtd::forms::control receives focus.
event< control, event_handler >	handle_created
	Occurs when a handle is created for the xtd::forms::control.
event< control, event_handler >	handle_destroyed
	Occurs when the control's handle is in the process of being destroyed.
event< control, event_handler >	enabled_changed
	Occurs when the value of the xtd::forms::control::enabled property changes.
event< control, event_handler >	fore_color_changed
	Occurs when the value of the xtd::forms::control::fore_color property changes.
event< control, event_handler >	font_changed
	Occurs when the value of the xtd::forms::control::font property changes.
event< control, help_event_handler >	help_requested
	Occurs when the user requests help for a xtd::forms::control.
event< control, key_event_handler >	key_down
	Occurs when a key is pressed while the xtd::forms::control has focus.
event< control, key_press_event_handler >	key_press
	Occurs when a character. space or backspace key is pressed while the xtd::forms::control has focus.
event< control, key_event_handler >	key_up
	Occurs when a key is released while the xtd::forms::control has focus.
event< control, event_handler >	layout
	Occurs when a xtd::forms::control should reposition its child controls.
event< control, event_handler >	location_changed
	Occurs when the value of the xtd::forms::control::location property changes.
event< control, event_handler >	lost_focus
	Occurs when the xtd::forms::control loses focus.
event< control, mouse_event_handler >	mouse_click
	Occurs when the xtd::forms::control is clicked by the mouse.
event< control, mouse_event_handler >	mouse_double_click
	Occurs when the xtd::forms::control is double clicked by the mouse.
event< control, mouse_event_handler >	mouse_down
	Occurs when the mouse pointer is over the xtd::forms::control and a mouse button is pressed.
event< control, event_handler >	mouse_enter
	Occurs when the mouse pointer enters the xtd::forms::control.
event< control, mouse_event_handler >	mouse_horizontal_wheel
	Occurs when the mouse horizontal wheel moves while the xtd::forms::control has focus.
event< control, event_handler >	mouse_leave
	Occurs when the mouse pointer leaves the xtd::forms::control.
event< control, mouse_event_handler >	mouse_move
	Occurs when the mouse pointer is moved over the xtd::forms::control.
event< control, mouse_event_handler >	mouse_up
	Occurs when the mouse pointer is over the xtd::forms::control and a mouse button is released.
event< control, mouse_event_handler >	mouse_wheel
	Occurs when the mouse wheel moves while the xtd::forms::control has focus.
event< control, event_handler >	move
	Occurs when the control is moved.
event< control, paint_event_handler >	paint
	Occurs when the xtd::forms::control is redrawn.
event< control, event_handler >	parent_changed
	Occurs when the value of the xtd::forms::control::parent property changes.
event< control, event_handler >	region_changed
	Occurs when the value of the xtd::forms::control::region property changes.
event< control, event_handler >	resize
	Occurs when the xtd::forms::control is resized.
event< control, event_handler >	right_to_left_changed
	Occurs when the value of the xtd::forms::control::right_to_left property changes.
event< control, event_handler >	size_changed
	Occurs when the value of the xtd::forms::control::size property changes.
event< control, event_handler >	style_sheet_changed
	Occurs when the value of the xtd::forms::control::style_sheet property changes or when xtd::application::style_sheet property changes.
event< control, event_handler >	system_colors_changed
	Occurs when the xtd::drwing::system_colors changes.
event< control, event_handler >	tab_stop_changed
	Occurs when the xtd::forms::control::tab_stop property value changes.
event< control, event_handler >	text_changed
	Occurs when the value of the xtd::forms::control::text property changes.
event< control, event_handler >	visible_changed
	Occurs when the value of the xtd::forms::control::visible property changes.
Static Public Attributes inherited from xtd::forms::list_control
static constexpr xtd::size	npos
	This is a special value equal to the maximum value representable by the type size_t.
Public Member Functions inherited from xtd::forms::list_control
Public Member Functions inherited from xtd::forms::control
	control ()
	Initializes a new instance of the xtd::forms::control class with default settings.
	control (const xtd::string &text)
	Initializes a new instance of the xtd::forms::control class with specific text.
	control (const control &parent, const xtd::string &text)
	Initializes a new instance of the xtd::forms::control class as a child control, with specific text.
	control (const xtd::string &text, int32 left, int32 top, int32 width, int32 height)
	Initializes a new instance of the control class with specific text, size, and location.
	control (const control &parent, const xtd::string &text, int32 left, int32 top, int32 width, int32 height)
	Initializes a new instance of the xtd::forms::control class as a child control, with specific text, size, and location.
virtual anchor_styles	anchor () const noexcept
	Gets the edges of the container to which a control is bound and determines how a control is resized with its parent.
virtual control &	anchor (xtd::forms::anchor_styles anchor)
	Gets the edges of the container to which a control is bound and determines how a control is resized with its parent.
virtual drawing::point	auto_scroll_point () const noexcept
	Gets where this control is scrolled to in scroll_control_into_view(control).
virtual bool	auto_size () const noexcept
	Gets a value that indicates whether the control resizes based on its contents.
virtual control &	auto_size (bool auto_size)
	Sets a value that indicates whether the control resizes based on its contents.
virtual drawing::color	back_color () const noexcept
	Gets the background color for the control.
virtual control &	back_color (const xtd::drawing::color &color)
	Sets the background color for the control.
virtual const xtd::drawing::image &	background_image () const noexcept
	Gets the background image displayed in the control.
virtual control &	background_image (const xtd::drawing::image &background_image)
	Sets the background image displayed in the control.
virtual xtd::forms::image_layout	background_image_layout () const noexcept
	Gets the background image layout as defined in the xtd::forms::image_layout enumeration.
virtual control &	background_image_layout (xtd::forms::image_layout background_image_layout)
	Sets the background image layout as defined in the xtd::forms::image_layout enumeration.
virtual int32	bottom () const noexcept
	Gets the distance, in pixels, between the bottom edge of the control and the top edge of its container's client area.
virtual drawing::rectangle	bounds () const noexcept
	Gets the size and location of the control including its nonclient elements, in pixels, relative to the parent control.
virtual control &	bounds (const xtd::drawing::rectangle &bounds)
	Sets the size and location of the control including its nonclient elements, in pixels, relative to the parent control.
virtual bool	can_focus () const noexcept
	Gets a value indicating whether the control can receive focus.
virtual bool	can_select () const noexcept
	Gets a value indicating whether the control can be selected.
bool	can_raise_events () const noexcept override
	Determines if events can be raised on the control.
virtual const drawing::rectangle &	client_rectangle () const noexcept
	Gets the rectangle that represents the client area of the control.
virtual const drawing::size &	client_size () const noexcept
	Gets the height and width of the client area of the control.
virtual control &	client_size (const xtd::drawing::size &client_size)
	Sets the height and width of the client area of the control.
virtual xtd::string	company_name () const noexcept
	Gets the name of the company or creator of the application containing the control.
virtual std::optional< context_menu_ref >	context_menu () const noexcept
	Gets the xtd::forms::context_menu that is displayed in the control.
virtual control &	context_menu (xtd::forms::context_menu &value)
	Sets the xtd::forms::context_menu that is displayed in the control.
virtual control &	context_menu (std::nullptr_t)
	Sets the xtd::forms::context_menu that is displayed in the control.
virtual forms::control_appearance	control_appearance () const noexcept
	Gets control appearance.
virtual control &	control_appearance (xtd::forms::control_appearance value)
	Sets control appearance.
virtual control_collection &	controls () noexcept
	Gets the collection of controls contained within the control.
virtual const control_collection &	controls () const noexcept
	Gets the collection of controls contained within the control.
virtual bool	created () const noexcept
	Gets a value indicating whether the control has been created.
virtual forms::cursor	cursor () const noexcept
	Gets the cursor that is displayed when the mouse pointer is over the control.
virtual control &	cursor (const xtd::forms::cursor &cursor)
	Sets the cursor that is displayed when the mouse pointer is over the control.
virtual drawing::rectangle	display_rectangle () const noexcept
	Gets the rectangle that represents the display area of the control.
virtual dock_style	dock () const noexcept
	Gets which control borders are docked to its parent control and determines how a control is resized with its parent.
virtual control &	dock (xtd::forms::dock_style dock)
	Sets which control borders are docked to its parent control and determines how a control is resized with its parent.
virtual bool	double_buffered () const noexcept
	Gets a value indicating whether this control should redraw its surface using a secondary buffer to reduce or prevent flicker.
virtual control &	double_buffered (bool double_buffered)
	Sets a value indicating whether this control should redraw its surface using a secondary buffer to reduce or prevent flicker.
virtual bool	enabled () const noexcept
	Gets a value indicating whether the control can respond to user interaction.
virtual control &	enabled (bool enabled)
	Sets a value indicating whether the control can respond to user interaction.
virtual bool	focused () const noexcept
	Gets a value indicating whether the control has input focus.
virtual drawing::font	font () const noexcept
	Gets the font of the text displayed by the control.
virtual control &	font (const xtd::drawing::font &font)
	Sets the font of the text displayed by the control.
virtual drawing::color	fore_color () const noexcept
	Gets the foreground color of the control.
virtual control &	fore_color (const xtd::drawing::color &color)
	Sets the foreground color of the control.
intptr	handle () const override
	Gets the window handle that the control is bound to.
virtual int32	height () const noexcept
	Gets the height of the control.
virtual control &	height (int32 height)
	Sets the height of the control.
bool	invoke_required () const noexcept override
	Gets a value indicating whether the caller must call an invoke method when making method calls to the control because the caller is on a different thread than the one the control was created on.
bool	is_handle_created () const noexcept
	Gets a value indicating whether the control has a handle associated with it.
virtual int32	left () const noexcept
	Gets the distance, in pixels, between the left edge of the control and the left edge of its container's client area.
virtual control &	left (int32 left)
	Sets the distance, in pixels, between the left edge of the control and the left edge of its container's client area.
virtual drawing::point	location () const noexcept
	Gets the coordinates of the upper-left corner of the control relative to the upper-left corner of its container.
virtual control &	location (const xtd::drawing::point &location)
	Sets the coordinates of the upper-left corner of the control relative to the upper-left corner of its container.
virtual forms::padding	margin () const noexcept
	Gets the space between controls.
virtual control &	margin (const xtd::forms::padding &margin)
	Sets the space between controls.
virtual const drawing::size &	maximum_client_size () const noexcept
	Gets the client size that is the upper limit that xtd::forms::control::get_preferred_size can specify.
virtual control &	maximum_client_size (const xtd::drawing::size &size)
	Sets the client size that is the upper limit that xtd::forms::control::get_preferred_size can specify.
virtual const drawing::size &	maximum_size () const noexcept
	Gets the size that is the upper limit that xtd::forms::control::get_preferred_size can specify.
virtual control &	maximum_size (const xtd::drawing::size &size)
	Sets the size that is the upper limit that xtd::forms::control::get_preferred_size can specify.
virtual const drawing::size &	minimum_client_size () const noexcept
	Gets the client size that is the lower limit that xtd::forms::control::get_preferred_size can specify.
virtual control &	minimum_client_size (const xtd::drawing::size &size)
	Sets the client size that is the lower limit that xtd::forms::control::get_preferred_size can specify.
virtual const drawing::size &	minimum_size () const noexcept
	Gets the size that is the lower limit that xtd::forms::control::get_preferred_size can specify.
virtual control &	minimum_size (const xtd::drawing::size &size)
	Sets the size that is the lower limit that xtd::forms::control::get_preferred_size can specify.
intptr	native_handle () const noexcept
	Gets the native handle that the control is bound to.
virtual const xtd::string &	name () const noexcept
	Gets the name of the control.
virtual control &	name (const xtd::string &name)
	Sets the name of the control.
virtual forms::padding	padding () const noexcept
	Gets padding within the control.
virtual control &	padding (const xtd::forms::padding &padding)
	Sets padding within the control.
virtual std::optional< control_ref >	parent () const noexcept
	Gets the parent container of the control.
virtual control &	parent (const control &parent)
	Sets the parent container of the control.
virtual control &	parent (std::nullptr_t)
	Resets the parent container of the control.
virtual xtd::string	product_name () const noexcept
	Gets the product name of the assembly containing the control.
bool	recreating_handle () const noexcept
	Gets a value indicating whether the control is currently re-creating its handle.
virtual const xtd::drawing::region &	region () const noexcept
	Gets the window region associated with the control.
virtual control &	region (const xtd::drawing::region &value)
	Sets the window region associated with the control.
virtual int32	right () const noexcept
	Gets the distance, in pixels, between the right edge of the control and the left edge of its container's client area.
virtual xtd::forms::right_to_left	right_to_left () const noexcept
	Gets a value indicating whether control's elements are aligned to support locales using right-to-left fonts.
virtual control &	right_to_left (xtd::forms::right_to_left value)
	Sets a value indicating whether control's elements are aligned to support locales using right-to-left fonts.
virtual drawing::size	size () const noexcept
	Gets the height and width of the control.
virtual control &	size (const drawing::size &size)
	Sets the height and width of the control.
virtual style_sheets::style_sheet	style_sheet () const noexcept
	Gets the contol style sheet.
virtual control &	style_sheet (const style_sheets::style_sheet &value)
	Sets the contol style sheet.
virtual control &	style_sheet (const xtd::string &value)
	Sets the contol style sheet.
virtual control &	style_sheet (std::nullptr_t)
	Resets the contol style sheet.
virtual bool	tab_stop () const noexcept
	Gets a value indicating whether the user can give the focus to this control using the TAB key.
virtual control &	tab_stop (bool value)
	Sets a value indicating whether the user can give the focus to this control using the TAB key.
virtual std::any	tag () const noexcept
	Gets the object that contains data about the control.
virtual control &	tag (std::any tag)
	Sets the object that contains data about the control.
virtual const xtd::string &	text () const noexcept
	Gets the text associated with this control.
intptr	toolkit_handle () const noexcept
	Gets the toolkit handle that the control is bound to.
virtual int32	top () const noexcept
	Gets the distance, in pixels, between the top edge of the control and the top edge of its container's client area.
virtual control &	top (int32 top)
	Sets the distance, in pixels, between the top edge of the control and the top edge of its container's client area.
virtual std::optional< control_ref >	top_level_control () const noexcept
	Gets the parent control that is not parented by another Windows Forms control. Typically, this is the outermost Form that the control is contained in.
virtual bool	visible () const noexcept
	Gets a value indicating whether the control and all its child controls are displayed.
virtual control &	visible (bool visible)
	Sets a value indicating whether the control and all its child controls are displayed.
virtual int32	width () const noexcept
	Gets the width of the control.
virtual control &	width (int32 width)
	Sets the width of the control.
xtd::async_result	begin_invoke (delegate< void()> method) override
	Executes the specified delegate asynchronously on the thread that the control's underlying handle was created on.
xtd::async_result	begin_invoke (delegate< void(std::vector< std::any >)> method, const std::vector< std::any > &args) override
	Executes the specified delegate asynchronously with the specified arguments, on the thread that the control's underlying handle was created on.
virtual void	bring_to_front ()
	Brings the control to the front of the z-order.
int32	compare_to (const control &value) const noexcept override
void	create_control ()
	Forces the creation of the visible control, including the creation of the handle and any visible child controls.
drawing::graphics	create_graphics () const
	Creates the xtd::drawing::graphics for the control.
virtual void	destroy_control ()
	Forces the destruction of the visible control, including the destruction of the handle and any visible child controls.
std::optional< object_ref >	end_invoke (xtd::async_result async) override
	Retrieves the return value of the asynchronous operation represented by the async_result_invoke passed.
bool	equals (const control &value) const noexcept override
bool	focus ()
	Sets input focus to the control.
auto_size_mode	get_auto_size_mode () const
	Gets a value indicating how a control will behave when its auto_size property is enabled.
size_t	get_child_index (intptr child) const
	Retrieves the index of a control within the control collection.
size_t	get_child_index (intptr child, bool &throw_exception) const
	Retrieves the index of the specified child control within the control collection, and optionally raises an exception if the specified control is not within the control collection.
virtual void	hide ()
	Conceals the control from the user.
virtual void	invalidate () const
	Invalidates the entire surface of the control and causes the control to be redrawn.
virtual void	invalidate (bool invalidate_children) const
	Invalidates a specific region of the control and causes a paint message to be sent to the control. Optionally, invalidates the child controls assigned to the control.
virtual void	invalidate (const drawing::rectangle &rect) const
	Invalidates the specified region of the control (adds it to the control's update region, which is the area that will be repainted at the next paint operation), and causes a paint message to be sent to the control.
virtual void	invalidate (const drawing::rectangle &rect, bool invalidate_children) const
	Invalidates the specified region of the control (adds it to the control's update region, which is the area that will be repainted at the next paint operation), and causes a paint message to be sent to the control. Optionally, invalidates the child controls assigned to the control.
virtual void	invalidate (const drawing::region &region) const
	Invalidates the specified region of the control (adds it to the control's update region, which is the area that will be repainted at the next paint operation), and causes a paint message to be sent to the control.
virtual void	invalidate (const drawing::region &region, bool invalidate_children) const
	Invalidates the specified region of the control (adds it to the control's update region, which is the area that will be repainted at the next paint operation), and causes a paint message to be sent to the control. Optionally, invalidates the child controls assigned to the control.
std::optional< object_ref >	invoke (delegate< void()> method) override
	Executes the specified delegate on the thread that owns the control's underlying window handle.
std::optional< object_ref >	invoke (delegate< void(std::vector< std::any >)> method, const std::vector< std::any > &args) override
	Executes the specified delegate, on the thread that owns the control's underlying window handle, with the specified list of arguments.
std::optional< object_ref >	invoke (delegate< void(std::vector< std::any >)> method, std::any arg) override
	Executes the specified delegate, on the thread that owns the control's underlying window handle, with the specified list of arguments.
void	perform_layout ()
	Forces the control to apply layout logic to all its child controls.
xtd::drawing::point	point_to_client (const xtd::drawing::point &p) const
	Computes the location of the specified screen point into client coordinates.
xtd::drawing::point	point_to_screen (const xtd::drawing::point &p) const
	Computes the location of the specified client point into screen coordinates.
bool	post_message (intptr hwnd, int32 msg, intptr wparam, intptr lparam) const
	Places (posts) a message in the message queue with specified hwnd, message, wparam and lparam.
virtual bool	pre_process_message (const xtd::forms::message &message)
	Preprocesses keyboard or input messages within the message loop before they are dispatched.
virtual void	refresh () const
	Forces the control to invalidate its client area and immediately redraw itself and any child controls.
void	resume_layout ()
	Resumes usual layout logic.
void	resume_layout (bool perform_layout)
	Resumes usual layout logic, optionally forcing an immediate layout of pending layout requests.
intptr	send_message (intptr hwnd, int32 msg, intptr wparam, intptr lparam) const
	Send a message with specified hwnd, message, wparam and lparam.
void	set_auto_size_mode (auto_size_mode auto_size_mode)
	Sets a value indicating how a control will behave when its auto_size property is enabled.
void	set_bounds (int32 x, int32 y, int32 width, int32 height)
	Sets the bounds of the control to the specified location and size.
void	set_bounds (int32 x, int32 y, int32 width, int32 height, bounds_specified specified)
	Sets the specified bounds of the control to the specified location and size.
virtual void	show ()
	Displays the control to the user.
void	suspend_layout ()
	Temporarily suspends the layout logic for the control.
xtd::string	to_string () const noexcept override
	Returns a string containing the name of the control, if any.
virtual void	update () const
	Causes the control to redraw the invalidated regions within its client area.
virtual xtd::async_result	begin_invoke (delegate< void()> method)=0
	Asynchronously executes the delegate on the thread that created this object.
virtual xtd::async_result	begin_invoke (delegate< void(std::vector< std::any >)> value, const std::vector< std::any > &args)=0
	Asynchronously executes the delegate on the thread that created this object.
virtual bool	equals (const object &obj) const noexcept
	Determines whether the specified object is equal to the current object.
virtual std::optional< object_ref >	invoke (delegate< void()> value)=0
	Synchronously executes the delegate on the thread that created this object and marshals the call to the creating thread.
virtual std::optional< object_ref >	invoke (delegate< void(std::vector< std::any >)> method, const std::vector< std::any > &args)=0
	Synchronously executes the delegate on the thread that created this object and marshals the call to the creating thread.
virtual std::optional< object_ref >	invoke (delegate< void(std::vector< std::any >)> method, std::any arg)=0
	Synchronously executes the delegate on the thread that created this object and marshals the call to the creating thread.
control &	operator<< (control &child)
	Add child control.
control &	operator>> (control &child)
	Remove child control.
Public Member Functions inherited from xtd::object
	object ()=default
	Create a new instance of the ultimate base class object.
virtual size_t	get_hash_code () const noexcept
	Serves as a hash function for a particular type.
virtual type_object	get_type () const noexcept
	Gets the type of the current instance.
template<typename object_t >
xtd::uptr< object_t >	memberwise_clone () const
	Creates a shallow copy of the current object.
Public Member Functions inherited from xtd::forms::iwin32_window
Public Member Functions inherited from xtd::iclonable
Public Member Functions inherited from xtd::icomparable< control >
virtual int32	compare_to (const control &obj) const noexcept=0
	Compares the current instance with another object of the same type.
Public Member Functions inherited from xtd::iequatable< control >
virtual bool	equals (const control &) const noexcept=0
	Indicates whether the current object is equal to another object of the same type.
Public Member Functions inherited from xtd::isynchronize_invoke
Static Public Member Functions inherited from xtd::forms::control
template<typename object_a_t , typename object_b_t >
static bool	equals (const object_a_t &object_a, const object_b_t &object_b) noexcept
	Determines whether the specified object instances are considered equal.
static bool	check_for_illegal_cross_thread_calls () noexcept
	Gets a value indicating whether to catch calls on the wrong thread that access a xtd::forms::contrtol::handle property when an application is being debugged.
static void	check_for_illegal_cross_thread_calls (bool value)
	Sets a value indicating whether to catch calls on the wrong thread that access a xtd::forms::contrtol::handle property when an application is being debugged.
static forms::keys	modifier_keys () noexcept
	Gets a value indicating which of the modifier keys (SHIFT, CTRL, and ALT) is in a pressed state.
static forms::mouse_buttons	mouse_buttons () noexcept
	Gets a value indicating which of the mouse buttons is in a pressed state.
static xtd::drawing::point	mouse_position () noexcept
	Gets the position of the mouse cursor in screen coordinates.
static control	create ()
	A factory to create a specified control.
static control	create (const drawing::point &location)
	A factory to create a specified control with specified location.
static control	create (const drawing::point &location, const drawing::size &size)
	A factory to create a specified control with specified location, and size.
static control	create (const drawing::point &location, const drawing::size &size, const xtd::string &name)
	A factory to create a specified control with specified location, size, and name.
static control	create (const control &paren)
	A factory to create a specified control with specified parent.
static control	create (const control &parent, const drawing::point &location)
	A factory to create a specified control with specified parent, location, size, and name.
static control	create (const control &parent, const drawing::point &location, const drawing::size &size)
	A factory to create a specified control with specified parent, location, and size.
static control	create (const control &parent, const drawing::point &location, const drawing::size &size, const xtd::string &name)
	A factory to create a specified control with specified parent, location, size, and name.
template<typename control_t >
static control_t	create ()
	A factory to create a specified control.
template<typename control_t >
static control_t	create (const drawing::point &location)
	A factory to create a specified control with specified location.
template<typename control_t >
static control_t	create (const drawing::point &location, const drawing::size &size)
	A factory to create a specified control with specified location, and size.
template<typename control_t >
static control_t	create (const drawing::point &location, const drawing::size &size, const xtd::string &name)
	A factory to create a specified control with specified location, size, and name.
template<typename control_t >
static control_t	create (const control &parent)
	A factory to create a specified control with specified parent.
template<typename control_t >
static control_t	create (const control &parent, const drawing::point &location)
	A factory to create a specified control with specified parent, and location.
template<typename control_t >
static control_t	create (const control &parent, const drawing::point &location, const drawing::size &size)
	A factory to create a specified control with specified parent, location, and size.
template<typename control_t >
static control_t	create (const control &parent, const drawing::point &location, const drawing::size &size, const xtd::string &name)
	A factory to create a specified control with specified parent, location, size, and name.
template<typename control_t >
static control_t	create (const xtd::string &text)
	A factory to create a specified control with specified text.
template<typename control_t >
static control_t	create (const xtd::string &text, const drawing::point &location)
	A factory to create a specified control with specified text, and location.
template<typename control_t >
static control_t	create (const xtd::string &text, const drawing::point &location, const drawing::size &size)
	A factory to create a specified control with specified text, location, and size.
template<typename control_t >
static control_t	create (const xtd::string &text, const drawing::point &location, const drawing::size &size, const xtd::string &name)
	A factory to create a specified control with specified text, location,size, and name.
template<typename control_t >
static control_t	create (const control &parent, const xtd::string &text)
	A factory to create a specified control with specified parent, and text.
template<typename control_t >
static control_t	create (const control &parent, const xtd::string &text, const drawing::point &location)
	A factory to create a specified control with specified parent, text, and location.
template<typename control_t >
static control_t	create (const control &parent, const xtd::string &text, const drawing::point &location, const drawing::size &size)
	A factory to create a specified control with specified parent, text, location, and size.
template<typename control_t >
static control_t	create (const control &parent, const xtd::string &text, const drawing::point &location, const drawing::size &size, const xtd::string &name)
	A factory to create a specified control with specified parent, text, location, size, and name.
static std::optional< control_ref >	from_child_handle (intptr handle)
	Retrieves the control that contains the specified handle.
static std::optional< control_ref >	from_handle (intptr handle)
	Returns the control that is currently associated with the specified handle.
Static Public Member Functions inherited from xtd::object
template<typename object_a_t , typename object_b_t >
static bool	equals (const object_a_t &object_a, const object_b_t &object_b) noexcept
	Determines whether the specified object instances are considered equal.
template<typename object_a_t , typename object_b_t >
static bool	reference_equals (const object_a_t &object_a, const object_b_t &object_b) noexcept
	Determines whether the specified object instances are the same instance.
Protected Member Functions inherited from xtd::forms::list_control
	list_control ()
	Initializes a new instance of the list_control class.
drawing::color	default_back_color () const noexcept override
	Gets the default background color of the control.
drawing::color	default_fore_color () const noexcept override
	Gets the default foreground color of the control.
virtual bool	allow_selection () const noexcept
	Gets a value indicating whether the list enables selection of list items.
virtual void	on_selected_index_changed (const event_args &e)
	Raises the list_control::selected_index_changed event.
void	set_selected_index (size_t value)
	Sets the currently selected item.
Protected Member Functions inherited from xtd::forms::control
xtd::forms::visual_styles::control_state	control_state () const noexcept
	Gets state.
virtual forms::cursor	default_cursor () const noexcept
	Gets the default cursor for the control.
virtual drawing::font	default_font () const noexcept
	Gets the default font of the control.
virtual drawing::size	default_size () const noexcept
	Gets the default size of the control.
xtd::uptr< xtd::object >	clone () const override
	Creates a new object that is a copy of the current instance.
virtual void	create_handle ()
	Creates a handle for the control.
virtual void	destroy_handle ()
	Destroys the handle associated with the control.
virtual void	def_wnd_proc (message &message)
	Sends the specified message to the default window procedure.
bool	get_style (control_styles flag) const noexcept
	Retrieves the value of the specified control style bit for the control.
virtual drawing::size	measure_control () const noexcept
	Measure this control.
drawing::size	measure_text () const noexcept
	Measure this control text.
virtual void	on_auto_size_changed (const event_args &e)
	Raises the xtd::forms::control::auto_size_changed event.
virtual void	on_back_color_changed (const event_args &e)
	Raises the xtd::forms::control::back_color_changed event.
virtual void	on_background_image_changed (const event_args &e)
	Raises the xtd::forms::control::background_image_changed event.
virtual void	on_background_image_layout_changed (const event_args &e)
	Raises the xtd::forms::control::background_image_layout_changed event.
virtual void	on_control_appearance_changed (const event_args &e)
	Raises the control::control_appearance_changed event.
virtual void	on_click (const event_args &e)
	Raises the xtd::forms::control::click event.
virtual void	on_client_size_changed (const event_args &e)
	Raises the xtd::forms::control::client_size_changed event.
virtual void	on_control_added (const control_event_args &e)
	Raises the xtd::forms::control::control_added event.
virtual void	on_control_removed (const control_event_args &e)
	Raises the xtd::forms::control::control_removed event.
virtual void	on_create_control ()
	Raises the xtd::forms::control::create_control event.
virtual void	on_cursor_changed (const event_args &e)
	Raises the xtd::forms::control::cursor_changed event.
virtual void	on_destroy_control ()
	Raises the xtd::forms::control::destroy_control event.
virtual void	on_dock_changed (const event_args &e)
	Raises the xtd::forms::control::dock_changed event.
virtual void	on_double_click (const event_args &e)
	Raises the xtd::forms::control::double_click event.
virtual void	on_enabled_changed (const event_args &e)
	Raises the xtd::forms::control::enabled_changed event.
virtual void	on_fore_color_changed (const event_args &e)
	Raises the xtd::forms::control::fore_color_changed event.
virtual void	on_font_changed (const event_args &e)
	Raises the xtd::forms::control::font_changed event.
virtual void	on_got_focus (const event_args &e)
	Raises the xtd::forms::control::got_focus event.
virtual void	on_handle_destroyed (const event_args &e)
	Raises the xtd::forms::control::handle_destroyed event.
virtual void	on_help_requested (help_event_args &e)
	Raises the xtd::forms::control::help_requested event.
virtual void	on_key_down (key_event_args &e)
	Raises the xtd::forms::control::key_down event.
virtual void	on_key_press (key_press_event_args &e)
	Raises the xtd::forms::control::key_press event.
virtual void	on_key_up (key_event_args &e)
	Raises the xtd::forms::control::key_up event.
virtual void	on_layout (const event_args &e)
	Raises the xtd::forms::control::layout event.
virtual void	on_location_changed (const event_args &e)
	Raises the xtd::forms::control::location_changed event.
virtual void	on_lost_focus (const event_args &e)
	Raises the xtd::forms::control::lost_focus event.
virtual void	on_mouse_click (const mouse_event_args &e)
	Raises the xtd::forms::control::mouse_click event.
virtual void	on_mouse_double_click (const mouse_event_args &e)
	Raises the xtd::forms::control::mouse_double_click event.
virtual void	on_mouse_down (const mouse_event_args &e)
	Raises the xtd::forms::control::mouse_down event.
virtual void	on_mouse_enter (const event_args &e)
	Raises the xtd::forms::control::mouse_enter event.
virtual void	on_mouse_horizontal_wheel (const mouse_event_args &e)
	Raises the xtd::forms::control::mouse_horizontal_wheel event.
virtual void	on_mouse_leave (const event_args &e)
	Raises the xtd::forms::control::mouse_leave event.
virtual void	on_mouse_move (const mouse_event_args &e)
	Raises the xtd::forms::control::mouse_move event.
virtual void	on_mouse_up (const mouse_event_args &e)
	Raises the xtd::forms::control::mouse_up event.
virtual void	on_mouse_wheel (const mouse_event_args &e)
	Raises the xtd::forms::control::mouse_wheel event.
virtual void	on_move (const event_args &e)
	Raises the xtd::forms::control::move event.
virtual void	on_paint (paint_event_args &e)
	Raises the xtd::forms::control::paint event.
virtual void	on_paint_background (paint_event_args &e)
	Paints the background of the xtd::forms::control.
virtual void	on_parent_back_color_changed (const event_args &e)
	Raises the xtd::forms::control::parent_back_color_changed event.
virtual void	on_parent_cursor_changed (const event_args &e)
	Raises the xtd::forms::control::parent_cursor_changed event.
virtual void	on_parent_changed (const event_args &e)
	Raises the xtd::forms::control::parent_changed event.
virtual void	on_parent_enabled_changed (const event_args &e)
	Raises the xtd::control::enabled_changed event when the xtd::control::enabled property value of the control's container changes..
virtual void	on_parent_fore_color_changed (const event_args &e)
	Raises the xtd::forms::control::parent_fore_color_changed event.
virtual void	on_parent_font_changed (const event_args &e)
	Raises the xtd::forms::control::parent_font_changed event.
virtual void	on_resize (const event_args &e)
	Raises the xtd::forms::control::region event.
virtual void	on_region_changed (const event_args &e)
	Raises the xtd::forms::control::region_changed event.
virtual void	on_right_to_left_changed (const event_args &e)
	Raises the xtd::forms::control::right_to_left_changed event.
virtual void	on_size_changed (const event_args &e)
	Raises the xtd::forms::control::size_changed event.
virtual void	on_style_sheet_changed (const event_args &e)
	Raises the xtd::forms::control::style_sheet_changed event.
virtual void	on_system_colors_changed (const event_args &e)
	Raises the control::system_colors_changed event.
virtual void	on_tab_stop_changed (const event_args &e)
	Raises the xtd::forms::control::tab_stop_changed event.
virtual void	on_text_changed (const event_args &e)
	Raises the xtd::forms::control::text_changed event.
virtual void	on_visible_changed (const event_args &e)
	Raises the xtd::forms::control::visible_changed event.
void	post_recreate_handle () noexcept
virtual void	recreate_handle ()
	Forces the re-creation of the handle for the control.
virtual void	set_bounds_core (int32 x, int32 y, int32 width, int32 height, bounds_specified specified)
	Performs the work of setting the specified bounds of this control.
void	set_can_focus (bool value)
	Sets a value indicating whether the control can receive focus.
virtual void	set_text (const xtd::string &text)
	Sets the text associated with this control.
virtual void	set_client_size_core (int32 width, int32 height)
	Sets the size of the client area of the control.
void	set_parent (intptr handle)
	Sets the parent handle of the control.
void	set_style (control_styles flag, bool value)
	Sets a specified control_styles flag to either true or false.
Protected Member Functions inherited from xtd::forms::component
	component ()
	Initialises a new instance of the component class.
bool	design_mode () const noexcept
	Gets a value that indicates whether the component is currently in design mode.
Static Protected Member Functions inherited from xtd::forms::control
static void	set_mouse_buttons (forms::mouse_buttons value)
	Sets a value indicating which of the mouse buttons is in a pressed state.

Constructor & Destructor Documentation

combo_box()

xtd::forms::combo_box::combo_box

(

)

Initializes a new instance of the combo_box class.

Member Function Documentation

dropped_down() [1/2]

bool xtd::forms::combo_box::dropped_down ( ) const

noexcept

Gets a value indicating whether the combo box is displaying its drop-down portion.

Returns

true if the drop-down portion is displayed; otherwise, false. The default is false.

dropped_down() [2/2]

combo_box & xtd::forms::combo_box::dropped_down

(

bool

value

)

Sets a value indicating whether the combo box is displaying its drop-down portion.

Parameters

value

true if the drop-down portion is displayed; otherwise, false. The default is false.

Warning

This feature is not supported on macOS.

drop_down_style() [1/2]

combo_box_style xtd::forms::combo_box::drop_down_style ( ) const

noexcept

Gets a value specifying the style of the combo box.

Returns

One of the combo_box_style values. The default is drop_down.

Remarks

The drop_down_style property specifies whether the list is always displayed or whether the list is displayed in a drop-down. The drop_down_style property also specifies whether the text portion can be edited. See combo_box_style for the available settings and their effects. There is no setting to always display the list and disallow entering a new value. To display a list to which no new values can be added, use a list_box control.

Examples

demo.cpp.

drop_down_style() [2/2]

combo_box & xtd::forms::combo_box::drop_down_style

(

combo_box_style

drop_down_style

)

Sets a value specifying the style of the combo box.

Parameters

droop_down_style

One of the combo_box_style values. The default is drop_down.

Remarks

The drop_down_style property specifies whether the list is always displayed or whether the list is displayed in a drop-down. The drop_down_style property also specifies whether the text portion can be edited. See combo_box_style for the available settings and their effects. There is no setting to always display the list and disallow entering a new value. To display a list to which no new values can be added, use a list_box control.

items() [1/3]

object_collection & xtd::forms::combo_box::items ( )

noexcept

Gets an object representing the collection of the items contained in this combo_box. Gets an object representing the collection of the items contained in this combo_box.

Returns

A combo_box::object_collection representing the items in the combo_box.

Remarks

This property enables you to obtain a reference to the list of items that are currently stored in the combo_box. With this reference, you can add items, remove items, and obtain a count of the items in the collection.

Examples

demo.cpp.

items() [2/3]

const object_collection & xtd::forms::combo_box::items ( ) const

noexcept

Gets an object representing the collection of the items contained in this combo_box. Gets an object representing the collection of the items contained in this combo_box.

Returns

A combo_box::object_collection representing the items in the combo_box.

items() [3/3]

const combo_box & xtd::forms::combo_box::items

(

const object_collection &

items

)

Sets an object representing the collection of the items contained in this combo_box. Gets an object representing the collection of the items contained in this combo_box.

Parameters

items

A combo_box::object_collection representing the items in the combo_box.

Returns

This instance of combo_box.

selected_index() [1/3]

list_control & xtd::forms::combo_box::selected_index ( size_t  selected_index )

overridevirtual

When overridden in a derived class, Sets the zero-based index of the currently selected item.

Parameters

selected_index

A zero-based index of the currently selected item. A value of negative one (-1) is returned if no item is selected.

Returns

Current list_control.

Implements xtd::forms::list_control.

Examples

demo.cpp.

selected_item() [1/2]

const item & xtd::forms::combo_box::selected_item ( ) const

noexcept

Gets currently selected item in the combo_box.

Returns

An object that represents the current selection in the control.

selected_item() [2/2]

combo_box & xtd::forms::combo_box::selected_item

(

const item &

selected_item

)

Sets currently selected item in the combo_box.

Parameters

selected_item

An object that represents the current selection in the control.

Returns

Current combo_box.

sorted() [1/2]

virtual bool xtd::forms::combo_box::sorted ( ) const

virtualnoexcept

Gets a value indicating whether the items in the combo_box are sorted alphabetically.

Returns

true if items in the control are sorted; otherwise, false. The default is false.

Remarks

Use the sorted property to automatically sort strings alphabetically in a combo_box. As items are added to a sorted combo_box, the items are moved to the appropriate location in the sorted list. When adding items to a list_box, it is more efficient to sort the items first and then add new items.

sorted() [2/2]

virtual combo_box & xtd::forms::combo_box::sorted ( bool  sorted )

virtual

Sets a value indicating whether the items in the combo_box are sorted alphabetically.

Parameters

sorted

true if items in the control are sorted; otherwise, false. The default is false.

Returns

Current combo_box.

Remarks

Use the sorted property to automatically sort strings alphabetically in a combo_box. As items are added to a sorted combo_box, the items are moved to the appropriate location in the sorted list. When adding items to a list_box, it is more efficient to sort the items first and then add new items.

text()

control & xtd::forms::combo_box::text ( const xtd::string &  text )

overridevirtual

Sets the text associated with this control.

Parameters

text	The text associated with this control.

Reimplemented from xtd::forms::control.

begin_update()

void xtd::forms::combo_box::begin_update

(

)

Maintains performance while items are added to the combo_box one at a time by preventing the control from drawing until the EndUpdate() method is called.

Remarks

The preferred way to add multiple items to the combo_box is to use the push_back_range method of the combo_box::object_collection class (through the items property of the list_box). This enables you to add an array of items to the list in a single operation. However, if you want to add items one at a time using the Add method of the list_box::object_collection class, you can use the begin_update method to prevent the control from repainting the list_box each time an item is added to the list. Once you have completed the task of adding items to the list, call the end_update method to enable the list_box to repaint. This way of adding items can prevent flickered drawing of the list_box when a large number of items are being added to the list.

end_update()

void xtd::forms::combo_box::end_update

(

)

Resumes painting the combo_box control after painting is suspended by the begin_update method.

Remarks

The preferred way to add multiple items to the combo_box is to use the push_back_range method of the combo_box::object_collection class (through the items property of the list_box). This enables you to add an array of items to the list in a single operation. However, if you want to add items one at a time using the Add method of the list_box::object_collection class, you can use the begin_update method to prevent the control from repainting the list_box each time an item is added to the list. Once you have completed the task of adding items to the list, call the end_update method to enable the list_box to repaint. This way of adding items can prevent flickered drawing of the list_box when a large number of items are being added to the list.

create() [1/24]

static combo_box xtd::forms::combo_box::create ( )

static

A factory to create an xtd::forms::combo_box.

Returns

New xtd::forms::combo_box created.

create() [2/24]

static combo_box xtd::forms::combo_box::create ( const drawing::point &  location )

static

A factory to create an xtd::forms::combo_box with specified location.

Parameters

location

A xtd::drawing::point that represent location of the xtd::forms::combo_box.

Returns

New xtd::forms::combo_box created.

create() [3/24]

static combo_box xtd::forms::combo_box::create ( const drawing::point &  location, const drawing::size &  size  )

static

A factory to create an xtd::forms::combo_box with specified location, and size.

Parameters

location	A xtd::drawing::point that represent location of the xtd::forms::combo_box.
size	A xtd::drawing::size that represent size of the xtd::forms::combo_box.

Returns

New xtd::forms::combo_box created.

create() [4/24]

static combo_box xtd::forms::combo_box::create ( const drawing::point &  location, const drawing::size &  size, const xtd::string &  name  )

static

A factory to create an xtd::forms::combo_box with specified location, size, and name.

Parameters

location	A xtd::drawing::point that represent location of the xtd::forms::combo_box.
size	A xtd::drawing::size that represent size of the xtd::forms::combo_box.
name	The name of the xtd::forms::combo_box.

Returns

New xtd::forms::combo_box created.

create() [5/24]

static combo_box xtd::forms::combo_box::create ( const object_collection &  items )

static

A factory to create an xtd::forms::combo_box with specified items.

Parameters

items

A choice::object_collection representing the items in the combo_box.

Returns

New xtd::forms::combo_box created.

create() [6/24]

static combo_box xtd::forms::combo_box::create ( const object_collection &  items, const drawing::point &  location  )

static

A factory to create an xtd::forms::combo_box with specified items, and location.

Parameters

items	A choice::object_collection representing the items in the combo_box.
location	A xtd::drawing::point that represent location of the xtd::forms::combo_box.

Returns

New xtd::forms::combo_box created.

create() [7/24]

static combo_box xtd::forms::combo_box::create ( const object_collection &  items, const drawing::point &  location, const drawing::size &  size  )

static

A factory to create an xtd::forms::combo_box with specified items, location, and size.

Parameters

items	A choice::object_collection representing the items in the combo_box.
location	A xtd::drawing::point that represent location of the xtd::forms::combo_box.
size	A xtd::drawing::size that represent size of the xtd::forms::combo_box.

Returns

New xtd::forms::combo_box created.

create() [8/24]

static combo_box xtd::forms::combo_box::create ( const object_collection &  items, const drawing::point &  location, const drawing::size &  size, const xtd::string &  name  )

static

A factory to create an xtd::forms::combo_box with specified items, location, size, and name.

Parameters

items	A choice::object_collection representing the items in the combo_box.
location	A xtd::drawing::point that represent location of the xtd::forms::combo_box.
size	A xtd::drawing::size that represent size of the xtd::forms::combo_box.
name	The name of the xtd::forms::combo_box.

Returns

New xtd::forms::combo_box created.

create() [9/24]

static combo_box xtd::forms::combo_box::create ( const object_collection &  items, size_t  selected_index  )

static

A factory to create an xtd::forms::combo_box with specified items, and selected_index.

Parameters

items	A choice::object_collection representing the items in the combo_box.
selected_index	A zero-based index of the currently selected item. The xtd::forms::combo_box::object_collection::npos is returned if no item is selected.

Returns

New xtd::forms::combo_box created.

create() [10/24]

static combo_box xtd::forms::combo_box::create ( const object_collection &  items, size_t  selected_index, const drawing::point &  location  )

static

A factory to create an xtd::forms::combo_box with specified items, selected_index, and location.

Parameters

items	A choice::object_collection representing the items in the combo_box.
selected_index	A zero-based index of the currently selected item. The xtd::forms::combo_box::object_collection::npos is returned if no item is selected.
location	A xtd::drawing::point that represent location of the xtd::forms::combo_box.

Returns

New xtd::forms::combo_box created.

create() [11/24]

static combo_box xtd::forms::combo_box::create ( const object_collection &  items, size_t  selected_index, const drawing::point &  location, const drawing::size &  size  )

static

A factory to create an xtd::forms::combo_box with specified items, selected_index, location, and size.

Parameters

items	A choice::object_collection representing the items in the combo_box.
selected_index	A zero-based index of the currently selected item. The xtd::forms::combo_box::object_collection::npos is returned if no item is selected.
location	A xtd::drawing::point that represent location of the xtd::forms::combo_box.
size	A xtd::drawing::size that represent size of the xtd::forms::combo_box.

Returns

New xtd::forms::combo_box created.

create() [12/24]

static combo_box xtd::forms::combo_box::create ( const object_collection &  items, size_t  selected_index, const drawing::point &  location, const drawing::size &  size, const xtd::string &  name  )

static

A factory to create an xtd::forms::combo_box with specified items, selected_index, location, size, and name.

Parameters

items	A choice::object_collection representing the items in the combo_box.
selected_index	A zero-based index of the currently selected item. The xtd::forms::combo_box::object_collection::npos is returned if no item is selected.
location	A xtd::drawing::point that represent location of the xtd::forms::combo_box.
size	A xtd::drawing::size that represent size of the xtd::forms::combo_box.
name	The name of the xtd::forms::combo_box.

Returns

New xtd::forms::combo_box created.

create() [13/24]

static combo_box xtd::forms::combo_box::create ( const control &  parent )

static

A factory to create an xtd::forms::combo_box with specified parent.

Parameters

parent

The parent that contains the new created xtd::forms::combo_box.

Returns

New xtd::forms::combo_box created.

create() [14/24]

static combo_box xtd::forms::combo_box::create ( const control &  parent, const drawing::point &  location  )

static

A factory to create an xtd::forms::combo_box with specified parent, and location.

Parameters

parent	The parent that contains the new created xtd::forms::combo_box.
location	A xtd::drawing::point that represent location of the xtd::forms::combo_box.

Returns

New xtd::forms::combo_box created.

create() [15/24]

static combo_box xtd::forms::combo_box::create ( const control &  parent, const drawing::point &  location, const drawing::size &  size  )

static

A factory to create an xtd::forms::combo_box with specified parent, location, and size.

Parameters

parent	The parent that contains the new created xtd::forms::combo_box.
location	A xtd::drawing::point that represent location of the xtd::forms::combo_box.
size	A xtd::drawing::size that represent size of the xtd::forms::combo_box.

Returns

New xtd::forms::combo_box created.

create() [16/24]

static combo_box xtd::forms::combo_box::create ( const control &  parent, const drawing::point &  location, const drawing::size &  size, const xtd::string &  name  )

static

A factory to create an xtd::forms::combo_box with specified parent, location, size, and name.

Parameters

parent	The parent that contains the new created xtd::forms::combo_box.
location	A xtd::drawing::point that represent location of the xtd::forms::combo_box.
size	A xtd::drawing::size that represent size of the xtd::forms::combo_box.
name	The name of the xtd::forms::combo_box.

Returns

New xtd::forms::combo_box created.

create() [17/24]

static combo_box xtd::forms::combo_box::create ( const control &  parent, const object_collection &  items  )

static

A factory to create an xtd::forms::combo_box with specified parent, and items.

Parameters

parent	The parent that contains the new created xtd::forms::combo_box.
items	A choice::object_collection representing the items in the combo_box.

Returns

New xtd::forms::combo_box created.

create() [18/24]

static combo_box xtd::forms::combo_box::create ( const control &  parent, const object_collection &  items, const drawing::point &  location  )

static

A factory to create an xtd::forms::combo_box with specified parent, items, and location.

Parameters

parent	The parent that contains the new created xtd::forms::combo_box.
items	A choice::object_collection representing the items in the combo_box.
location	A xtd::drawing::point that represent location of the xtd::forms::combo_box.

Returns

New xtd::forms::combo_box created.

create() [19/24]

static combo_box xtd::forms::combo_box::create ( const control &  parent, const object_collection &  items, const drawing::point &  location, const drawing::size &  size  )

static

A factory to create an xtd::forms::combo_box with specified parent, items, location, and size.

Parameters

parent	The parent that contains the new created xtd::forms::combo_box.
items	A choice::object_collection representing the items in the combo_box.
location	A xtd::drawing::point that represent location of the xtd::forms::combo_box.
size	A xtd::drawing::size that represent size of the xtd::forms::combo_box.

Returns

New xtd::forms::combo_box created.

create() [20/24]

static combo_box xtd::forms::combo_box::create ( const control &  parent, const object_collection &  items, const drawing::point &  location, const drawing::size &  size, const xtd::string &  name  )

static

A factory to create an xtd::forms::combo_box with specified parent, items, location, size, and name.

Parameters

parent	The parent that contains the new created xtd::forms::combo_box.
items	A choice::object_collection representing the items in the combo_box.
location	A xtd::drawing::point that represent location of the xtd::forms::combo_box.
size	A xtd::drawing::size that represent size of the xtd::forms::combo_box.
name	The name of the xtd::forms::combo_box.

Returns

New xtd::forms::combo_box created.

create() [21/24]

static combo_box xtd::forms::combo_box::create ( const control &  parent, const object_collection &  items, size_t  selected_index  )

static

A factory to create an xtd::forms::combo_box with specified parent, items, and selected_index.

Parameters

parent	The parent that contains the new created xtd::forms::combo_box.
items	A choice::object_collection representing the items in the combo_box.
selected_index	A zero-based index of the currently selected item. The xtd::forms::combo_box::object_collection::npos is returned if no item is selected.

Returns

New xtd::forms::combo_box created.

create() [22/24]

static combo_box xtd::forms::combo_box::create ( const control &  parent, const object_collection &  items, size_t  selected_index, const drawing::point &  location  )

static

A factory to create an xtd::forms::combo_box with specified parent, items, selected_index, and location.

Parameters

parent	The parent that contains the new created xtd::forms::combo_box.
items	A choice::object_collection representing the items in the combo_box.
selected_index	A zero-based index of the currently selected item. The xtd::forms::combo_box::object_collection::npos is returned if no item is selected.
location	A xtd::drawing::point that represent location of the xtd::forms::combo_box.

Returns

New xtd::forms::combo_box created.

create() [23/24]

static combo_box xtd::forms::combo_box::create ( const control &  parent, const object_collection &  items, size_t  selected_index, const drawing::point &  location, const drawing::size &  size  )

static

A factory to create an xtd::forms::combo_box with specified parent, items, selected_index, location, and size.

Parameters

parent	The parent that contains the new created xtd::forms::combo_box.
items	A choice::object_collection representing the items in the combo_box.
selected_index	A zero-based index of the currently selected item. The xtd::forms::combo_box::object_collection::npos is returned if no item is selected.
location	A xtd::drawing::point that represent location of the xtd::forms::combo_box.
size	A xtd::drawing::size that represent size of the xtd::forms::combo_box.

Returns

New xtd::forms::combo_box created.

create() [24/24]

static combo_box xtd::forms::combo_box::create ( const control &  parent, const object_collection &  items, size_t  selected_index, const drawing::point &  location, const drawing::size &  size, const xtd::string &  name  )

static

A factory to create an xtd::forms::combo_box with specified parent, items, selected_index, location, size, and name.

Parameters

parent	The parent that contains the new created xtd::forms::combo_box.
items	A choice::object_collection representing the items in the combo_box.
selected_index	A zero-based index of the currently selected item. The xtd::forms::combo_box::object_collection::npos is returned if no item is selected.
location	A xtd::drawing::point that represent location of the xtd::forms::combo_box.
size	A xtd::drawing::size that represent size of the xtd::forms::combo_box.
name	The name of the xtd::forms::combo_box.

Returns

New xtd::forms::combo_box created.

create_params()

forms::create_params xtd::forms::combo_box::create_params ( ) const

overrideprotectedvirtualnoexcept

Gets the required creation parameters when the control handle is created.

Returns

A create_params that contains the required creation parameters when the handle to the control is created.

Remarks

The create_params property should not be overridden and used to adjust the properties of your derived control. Properties such as the create_params::caption, create_params::width, and create_params::height should be set by the corresponding properties in your control such as control::text, control::width and control::height. The create_params should only be extended when you are wrapping a standard Windows control class or to set styles not provided by the forms namespace.

Notes for inheritors

When overriding the create_params property in a derived class, use the base class's create_params property to extend the base implementation. Otherwise, you must provide all the implementation.

Reimplemented from xtd::forms::control.

clone()

xtd::uptr< xtd::object > xtd::forms::combo_box::clone ( ) const

overrideprotectedvirtual

Creates a new object that is a copy of the current instance.

Returns

A new object that is a copy of this instance.

Notes to Implementers

All controls must be override the clone method.

Implements xtd::iclonable.

on_drop_down()

virtual void xtd::forms::combo_box::on_drop_down ( const event_args &  e )

protectedvirtual

Raises the xtd::forms::combo_box::drop_down event.

Remarks

This event is raised each time the drop-down is displayed.

Raising an event invokes the event handler through a delegate. For more information about handling events, see Handling and Raising Events.

The xtd::forms::combo_box::on_drop_down method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

on_drop_down_closed()

virtual void xtd::forms::combo_box::on_drop_down_closed ( const event_args &  e )

protectedvirtual

Raises the xtd::forms::combo_box::drop_down_closed event.

Remarks

Raising an event invokes the event handler through a delegate. For more information about handling events, see Handling and Raising Events.

The xtd::forms::combo_box::on_drop_down_closed method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

on_drop_down_style_changed()

virtual void xtd::forms::combo_box::on_drop_down_style_changed ( const event_args &  e )

protectedvirtual

Raises the xtd::forms::combo_box::drop_down_style_changed event.

Remarks

This event is raised when you set xtd::forms::combo_box::drop_down_style to a new value.

Raising an event invokes the event handler through a delegate. For more information about handling events, see Handling and Raising Events.

The xtd::forms::combo_box::on_drop_down_style_changed method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

on_handle_created()

void xtd::forms::combo_box::on_handle_created ( const event_args &  e )

overrideprotectedvirtual

Raises the xtd::forms::control::handle_created event.

Parameters

e	An xtd::event_args that contains the event data.

Reimplemented from xtd::forms::control.

on_selected_value_changed()

void xtd::forms::combo_box::on_selected_value_changed ( const event_args &  e )

overrideprotectedvirtual

Raises the list_control::selected_value_changed event.

Reimplemented from xtd::forms::list_control.

wnd_proc()

void xtd::forms::combo_box::wnd_proc ( message &  m )

overrideprotectedvirtual

Processes Windows messages.

Parameters

m	The Windows Message to process.

Remarks

All messages are sent to the wnd_proc method after getting filtered through the pre_process_message method.

Notes to Inheritors

Inheriting controls should call the base class's wnd_proc(message&) method to process any messages that they do not handle.

Reimplemented from xtd::forms::control.

selected_index() [2/3]

virtual size_t xtd::forms::list_control::selected_index ( ) const

virtualnoexcept

Gets the zero-based index of the currently selected item.

Returns

A zero-based index of the currently selected item. A value of negative one (-1) is returned if no item is selected.

Reimplemented from xtd::forms::list_control.

selected_index() [3/3]

virtual list_control & xtd::forms::list_control::selected_index ( size_t  selected_index )

virtual

When overridden in a derived class, Sets the zero-based index of the currently selected item.

Parameters

selected_index

A zero-based index of the currently selected item. A value of negative one (-1) is returned if no item is selected.

Returns

Current list_control.

Implements xtd::forms::list_control.

Member Data Documentation

drop_down

event<combo_box, event_handler> xtd::forms::combo_box::drop_down

Occurs when the drop-down portion of a xtd::forms::combo_box is shown.

Remarks

For more information about handling events, see Handling and Raising Events.

drop_down_closed

event<combo_box, event_handler> xtd::forms::combo_box::drop_down_closed

Occurs when the drop-down portion of the xtd::forms::combo_box is no longer visible.

Remarks

For more information about handling events, see Handling and Raising Events.

drop_down_style_changed

event<combo_box, event_handler> xtd::forms::combo_box::drop_down_style_changed

Occurs when the drop_down_style property has changed.

Remarks

For more information about handling events, see Handling and Raising Events.

---

The documentation for this class was generated from the following file:

• xtd.forms/include/xtd/forms/combo_box.hpp