#include <combo_box.h>

Definition

Represents a Windows combo box control.

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.

Examples: The following code example demonstrate the use of combo box control.
#include <xtd/xtd>

using namespace xtd;

using namespace xtd::drawing;

using namespace xtd::forms;

namespace examples {

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_click);

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_click);

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_click);

}

private:

void on_combo_box_click(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;

};

}

int main() {

application::run(examples::form1());

}

xtd::event_args
Represents the base class for classes that contain event data, and provides a value to use for events...
Definition: event_args.h:18

xtd::forms::application::run
static void run()
Begins running a standard application message loop on the current thread, without a form.

xtd::forms::combo_box::combo_box
combo_box()
Initializes a new instance of the combo_box class.

xtd::forms::combo_box::selected_index
virtual size_t selected_index() const
Gets the zero-based index of the currently selected item.
Definition: list_control.h:84

xtd::forms::control::controls
virtual control_collection & controls()
Gets the collection of controls contained within the control.
Definition: control.h:365

xtd::forms::control::text
virtual const xtd::ustring & text() const
Gets the text associated with this control.
Definition: control.h:650

xtd::forms::layout::arranged_element_collection::push_back_range
void push_back_range(const arranged_element_collection &collection)
Adds elements to the end.
Definition: arranged_element_collection.h:369

xtd::event_handler
generic_event_handler<> event_handler
Represents the method that will handle an event that has no event data.
Definition: event_handler.h:33

xtd::forms::combo_box_style::drop_down_list
@ drop_down_list
Specifies that the list is displayed by clicking the down arrow and that the text portion is not edit...

xtd::forms::combo_box_style::simple
@ simple
Specifies that the list is always visible and that the text portion is editable. This means that the ...

xtd::drawing
The xtd::drawing namespace provides access to GDI+ basic graphics functionality. More advanced functi...
Definition: bitmap.h:11

xtd::forms
The xtd::forms namespace contains classes for creating Windows-based applications that take full adva...
Definition: about_box.h:13

xtd
The xtd namespace contains all fundamental classes to access Hardware, Os, System,...
Definition: system_report.h:17

Public Attributes
event< combo_box, event_handler >	drop_down_style_changed
	Occurs when the drop_down_style property has changed. More...

Public Attributes inherited from xtd::forms::list_control
event< list_control, event_handler >	selected_index_changed
	Occurs when the selected_index property changes. More...

event< list_control, event_handler >	selected_value_changed
	Occurs when the selected_value property changes. More...

Public Attributes inherited from xtd::forms::control
event< control, event_handler >	auto_size_changed
	Occurs when the value of the auto_size property changes. More...

event< control, event_handler >	back_color_changed
	Occurs when the value of the back_color property changes. More...

event< control, event_handler >	background_image_changed
	Occurs when the value of the background_image property changes. More...

event< control, event_handler >	background_image_layout_changed
	Occurs when the value of the background_image_layout property changes. More...

event< control, event_handler >	click
	Occurs when the control is clicked. More...

event< control, event_handler >	client_size_changed
	Occurs when the value of the client_size property changes. More...

event< control, control_event_handler >	control_added
	Occurs when a new control is added to the control::control_collection. More...

event< control, control_event_handler >	control_removed
	Occurs when a new control is removed to the control::control_collection. More...

event< control, event_handler >	cursor_changed
	Occurs when the value of the cursor property changes. More...

event< control, event_handler >	dock_changed
	Occurs when the value of the dock property changes. More...

event< control, event_handler >	double_click
	Occurs when the control is double-clicked. More...

event< control, event_handler >	enabled_changed
	Occurs when the value of the enabled property changes. More...

event< control, event_handler >	font_changed
	Occurs when the value of the font property changes. More...

event< control, event_handler >	fore_color_changed
	Occurs when the value of the fore_color property changes. More...

event< control, event_handler >	got_focus
	Occurs when the control receives focus. More...

event< control, event_handler >	handle_created
	Occurs when a handle is created for the control. More...

event< control, event_handler >	handle_destroyed
	Occurs when the control's handle is in the process of being destroyed. More...

event< control, key_event_handler >	key_down
	Occurs when a key is pressed while the control has focus. More...

event< control, key_press_event_handler >	key_press
	Occurs when a character. space or backspace key is pressed while the control has focus. More...

event< control, key_event_handler >	key_up
	Occurs when a key is released while the control has focus. More...

event< control, event_handler >	layout
	Occurs when a control should reposition its child controls. More...

event< control, event_handler >	location_changed
	Occurs when the value of the location property changes. More...

event< control, event_handler >	lost_focus
	Occurs when the control loses focus. More...

event< control, mouse_event_handler >	mouse_click
	Occurs when the control is clicked by the mouse. More...

event< control, mouse_event_handler >	mouse_double_click
	Occurs when the control is double clicked by the mouse. More...

event< control, mouse_event_handler >	mouse_down
	Occurs when the mouse pointer is over the control and a mouse button is pressed. More...

event< control, event_handler >	mouse_enter
	Occurs when the mouse pointer enters the control. More...

event< control, mouse_event_handler >	mouse_horizontal_wheel
	Occurs when the mouse horizontal wheel moves while the control has focus. More...

event< control, event_handler >	mouse_leave
	Occurs when the mouse pointer leaves the control. More...

event< control, mouse_event_handler >	mouse_move
	Occurs when the mouse pointer is moved over the control. More...

event< control, mouse_event_handler >	mouse_up
	Occurs when the mouse pointer is over the control and a mouse button is released. More...

event< control, mouse_event_handler >	mouse_wheel
	Occurs when the mouse wheel moves while the control has focus. More...

event< control, paint_event_handler >	paint
	Occurs when the control is redrawn. More...

event< control, event_handler >	parent_changed
	Occurs when the value of the parent property changes. More...

event< control, event_handler >	resize
	Occurs when the control is resized. More...

event< control, event_handler >	size_changed
	Occurs when the value of the size property changes. More...

event< control, event_handler >	text_changed
	Occurs when the value of the text property changes. More...

event< control, event_handler >	visible_changed
	Occurs when the value of the visible property changes. More...

Public Member Functions
	combo_box ()
	Initializes a new instance of the combo_box class. More...

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. More...

virtual drawing::size	default_size () const override
	Gets the default size of the control. More...

combo_box_style	drop_down_style () const
	Gets a value specifying the style of the combo box. More...

combo_box &	drop_down_style (combo_box_style drop_down_style)
	Sets a value specifying the style of the combo box. More...

void	end_update ()
	Resumes painting the combo_box control after painting is suspended by the begin_update method. More...

object_collection &	items ()
	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. More...

const object_collection &	items () const
	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. More...

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. More...

virtual size_t	selected_index () const
	Gets the zero-based index of the currently selected item. More...

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. More...

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. More...

const item &	selected_item () const
	Gets currently selected item in the combo_box. More...

combo_box &	selected_item (const item &selected_item)
	Sets currently selected item in the combo_box. More...

virtual bool	sorted () const
	Gets a value indicating whether the items in the combo_box are sorted alphabetically. More...

virtual combo_box &	sorted (bool sorted)
	Sets a value indicating whether the items in the combo_box are sorted alphabetically. More...

control &	text (const xtd::ustring &text) override
	Sets the text associated with this control. More...

Public Member Functions inherited from xtd::forms::list_control
virtual size_t	selected_index () const
	Gets the zero-based index of the currently selected item. More...

Public Member Functions inherited from xtd::forms::control
	control ()
	Initializes a new instance of the control class with default settings. More...

	control (const control &parent, const xtd::ustring &text)
	Initializes a new instance of the control class as a child control, with specific text. More...

	control (const control &parent, const xtd::ustring &text, int32_t left, int32_t top, int32_t width, int32_t height)
	Initializes a new instance of the control class as a child control, with specific text, size, and location. More...

	control (const xtd::ustring &text)
	Initializes a new instance of the control class with specific text. More...

	control (const xtd::ustring &text, int32_t left, int32_t top, int32_t width, int32_t height)
	Initializes a new instance of the control class with specific text, size, and location. More...

virtual anchor_styles	anchor () const
	Gets the edges of the container to which a control is bound and determines how a control is resized with its parent. More...

virtual control &	anchor (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. More...

virtual drawing::point	auto_scroll_point () const
	Gets where this control is scrolled to in scroll_control_into_view(control). More...

virtual bool	auto_size () const
	Gets a value that indicates whether the control resizes based on its contents. More...

virtual control &	auto_size (bool auto_size)
	Sets a value that indicates whether the control resizes based on its contents. More...

virtual drawing::color	back_color () const
	Gets the background color for the control. More...

virtual control &	back_color (const drawing::color &color)
	Sets the background color for the control. More...

virtual const xtd::drawing::image &	background_image () const
	Gets the background image displayed in the control. More...

virtual control &	background_image (const xtd::drawing::image &background_image)
	Sets the background image displayed in the control. More...

virtual xtd::forms::image_layout	background_image_layout () const
	Gets the background image layout as defined in the xtd::forms::image_layout enumeration. More...

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. More...

std::shared_ptr< xtd::iasync_result >	begin_invoke (delegate< void()> value)
	Executes the specified delegate asynchronously on the thread that the control's underlying handle was created on. More...

std::shared_ptr< xtd::iasync_result >	begin_invoke (delegate< void(std::vector< std::any >)> value, const std::vector< std::any > &args)
	Executes the specified delegate asynchronously with the specified arguments, on the thread that the control's underlying handle was created on. More...

virtual int32_t	bottom () const
	Gets the distance, in pixels, between the bottom edge of the control and the top edge of its container's client area. More...

virtual drawing::rectangle	bounds () const
	Gets the size and location of the control including its nonclient elements, in pixels, relative to the parent control. More...

virtual control &	bounds (const drawing::rectangle &bounds)
	Sets the size and location of the control including its nonclient elements, in pixels, relative to the parent control. More...

virtual void	bring_to_front ()
	Brings the control to the front of the z-order. More...

virtual bool	can_focus () const
	Gets a value indicating whether the control can receive focus. More...

bool	can_raise_events () const override
	Determines if events can be raised on the control. More...

virtual bool	can_select () const
	Gets a value indicating whether the control can be selected. More...

virtual const drawing::rectangle &	client_rectangle () const
	Gets the rectangle that represents the client area of the control. More...

virtual const drawing::size &	client_size () const
	Gets the height and width of the client area of the control. More...

virtual control &	client_size (const drawing::size &client_size)
	Sets the height and width of the client area of the control. More...

virtual xtd::ustring	company_name () const
	Gets the name of the company or creator of the application containing the control. More...

virtual control_collection &	controls ()
	Gets the collection of controls contained within the control. More...

virtual const control_collection &	controls () const
	Gets the collection of controls contained within the control. More...

void	create_control ()
	Forces the creation of the visible control, including the creation of the handle and any visible child controls. More...

drawing::graphics	create_graphics () const
	Creates the xtd::drawing::graphics for the control. More...

virtual void	create_handle ()
	Creates a handle for the control. More...

virtual bool	created ()
	Gets a value indicating whether the control has been created. More...

virtual forms::cursor	cursor () const
	Gets the cursor that is displayed when the mouse pointer is over the control. More...

virtual control &	cursor (const forms::cursor &cursor)
	Sets the cursor that is displayed when the mouse pointer is over the control. More...

virtual forms::cursor	default_cursor () const
	Gets the default cursor for the control. More...

virtual drawing::font	default_font () const
	Gets the default font of the control. More...

virtual void	destroy_control ()
	Forces the destruction of the visible control, including the destruction of the handle and any visible child controls. More...

virtual void	destroy_handle ()
	Destroys the handle associated with the control. More...

virtual drawing::rectangle	display_rectangle () const
	Gets the rectangle that represents the display area of the control. More...

virtual dock_style	dock () const
	Gets or sets which control borders are docked to its parent control and determines how a control is resized with its parent. More...

virtual control &	dock (dock_style dock)
	Sets or sets which control borders are docked to its parent control and determines how a control is resized with its parent. More...

virtual bool	double_buffered () const
	Gets a value indicating whether this control should redraw its surface using a secondary buffer to reduce or prevent flicker. More...

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. More...

virtual bool	enabled () const
	Gets a value indicating whether the control can respond to user interaction. More...

virtual control &	enabled (bool enabled)
	Sets a value indicating whether the control can respond to user interaction. More...

void	end_invoke (std::shared_ptr< xtd::iasync_result > async)
	Retrieves the return value of the asynchronous operation represented by the async_result_invoke passed. More...

bool	focus ()
	Sets input focus to the control. More...

virtual bool	focused () const
	Gets a value indicating whether the control has input focus. More...

virtual drawing::font	font () const
	Gets the font of the text displayed by the control. More...

virtual control &	font (const drawing::font &font)
	Sets the font of the text displayed by the control. More...

virtual drawing::color	fore_color () const
	Gets the foreground color of the control. More...

virtual control &	fore_color (const drawing::color &color)
	Sets the foreground color of the control. More...

size_t	get_child_index (intptr_t child) const
	Retrieves the index of a control within the control collection. More...

size_t	get_child_index (intptr_t 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. More...

intptr_t	handle () const override
	Gets the window handle that the control is bound to. More...

virtual int32_t	height () const
	Gets the height of the control. More...

virtual control &	height (int32_t height)
	Sets the height of the control. More...

virtual void	hide ()
	Conceals the control from the user. More...

virtual void	invalidate () const
	Invalidates the entire surface of the control and causes the control to be redrawn. More...

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. More...

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. More...

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. More...

void	invoke (delegate< void()> value)
	Executes the specified delegate on the thread that owns the control's underlying window handle. More...

void	invoke (delegate< void(std::vector< std::any >)> value, const std::vector< std::any > &args)
	Executes the specified delegate, on the thread that owns the control's underlying window handle, with the specified list of arguments. More...

bool	is_handle_created () const
	Gets a value indicating whether the control has a handle associated with it. More...

virtual int32_t	left () const
	Gets the distance, in pixels, between the left edge of the control and the left edge of its container's client area. More...

virtual control &	left (int32_t left)
	Sets the distance, in pixels, between the left edge of the control and the left edge of its container's client area. More...

virtual drawing::point	location () const
	Gets the coordinates of the upper-left corner of the control relative to the upper-left corner of its container. More...

virtual control &	location (const drawing::point &location)
	Sets the coordinates of the upper-left corner of the control relative to the upper-left corner of its container. More...

virtual forms::padding	margin () const
	Gets the space between controls. More...

virtual control &	margin (const forms::padding &margin)
	Sets the space between controls. More...

virtual const drawing::size &	maximum_size () const
	Gets the size that is the upper limit that xtd::forms::control::get_preferred_size can specify. More...

virtual control &	maximum_size (const drawing::size &size)
	Sets the size that is the upper limit that xtd::forms::control::get_preferred_size can specify. More...

virtual const drawing::size &	minimum_size () const
	Gets the size that is the lower limit that xtd::forms::control::get_preferred_size can specify. More...

virtual control &	minimum_size (const drawing::size &size)
	Sets the size that is the lower limit that xtd::forms::control::get_preferred_size can specify. More...

virtual const xtd::ustring &	name () const
	Gets the name of the control. More...

virtual control &	name (const xtd::ustring &name)
	Sets the name of the control. More...

virtual forms::padding	padding () const
	Gets padding within the control. More...

virtual control &	padding (const forms::padding &padding)
	Sets padding within the control. More...

virtual std::optional< control_ref >	parent () const
	Gets the parent container of the control. More...

virtual control &	parent (const control &parent)
	Sets the parent container of the control. More...

virtual control &	parent (std::nullptr_t)
	Resets the parent container of the control. More...

void	perform_layout ()
	Forces the control to apply layout logic to all its child controls. More...

xtd::drawing::point	point_to_client (const xtd::drawing::point &p)
	Computes the location of the specified screen point into client coordinates. More...

xtd::drawing::point	point_to_screen (const xtd::drawing::point &p)
	Computes the location of the specified client point into screen coordinates. More...

virtual bool	pre_process_message (xtd::forms::message &message)
	Preprocesses keyboard or input messages within the message loop before they are dispatched. More...

virtual xtd::ustring	product_name () const
	Gets the product name of the assembly containing the control. More...

bool	recreating_handle () const
	Gets a value indicating whether the control is currently re-creating its handle. More...

virtual void	refresh () const
	Forces the control to invalidate its client area and immediately redraw itself and any child controls. More...

void	resume_layout ()
	Resumes usual layout logic. More...

void	resume_layout (bool perform_layout)
	Resumes usual layout logic, optionally forcing an immediate layout of pending layout requests. More...

virtual int32_t	right () const
	Gets the distance, in pixels, between the right edge of the control and the left edge of its container's client area. More...

intptr_t	send_message (intptr_t hwnd, int32_t msg, intptr_t wparam, intptr_t lparam) const
	Send a message with specified hwnd, message, wparam and lparam. More...

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. More...

void	set_bounds (int32_t x, int32_t y, int32_t width, int32_t height)
	Sets the bounds of the control to the specified location and size. More...

void	set_bounds (int32_t x, int32_t y, int32_t width, int32_t height, bounds_specified specified)
	Sets the specified bounds of the control to the specified location and size. More...

virtual void	show ()
	Displays the control to the user. More...

virtual const drawing::size &	size () const
	Gets the height and width of the control. More...

virtual control &	size (const drawing::size &size)
	Sets the height and width of the control. More...

void	suspend_layout ()
	Temporarily suspends the layout logic for the control. More...

virtual std::any	tag () const
	Gets the object that contains data about the control. More...

virtual control &	tag (std::any tag)
	Sets the object that contains data about the control. More...

virtual const xtd::ustring &	text () const
	Gets the text associated with this control. More...

xtd::ustring	to_string () const noexcept override
	Returns a string containing the name of the control, if any. More...

virtual int32_t	top () const
	Gets the distance, in pixels, between the top edge of the control and the top edge of its container's client area. More...

virtual control &	top (int32_t top)
	Sets the distance, in pixels, between the top edge of the control and the top edge of its container's client area. More...

virtual std::optional< control_ref >	top_level_control () const
	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. More...

virtual void	update () const
	Causes the control to redraw the invalidated regions within its client area. More...

virtual bool	visible () const
	Gets a value indicating whether the control and all its child controls are displayed. More...

virtual control &	visible (bool visible)
	Sets a value indicating whether the control and all its child controls are displayed. More...

virtual int32_t	width () const
	Gets the width of the control. More...

virtual control &	width (int32_t width)
	Sets the width of the control. More...

Public Member Functions inherited from xtd::object
	object ()=default
	Create a new instance of the ultimate base class object. More...

virtual bool	equals (const object &obj) const noexcept
	Determines whether the specified object is equal to the current object. More...

virtual size_t	get_hash_code () const noexcept
	Serves as a hash function for a particular type. More...

template<typename object_t >
std::unique_ptr< object_t >	memberwise_clone () const
	Gets the type of the current instance. More...

Protected Member Functions
forms::create_params	create_params () const override
	Gets the required creation parameters when the control handle is created. More...

virtual void	on_drop_down_style_changed (const event_args &e)
	Raises the combo_box::drop_down_style_changed event. More...

void	on_handle_created (const event_args &e) override
	Raises the control::handle_created event. More...

void	on_selected_value_changed (const event_args &e) override
	Raises the list_control::selected_value_changed event. More...

void	set_bounds_core (int32_t x, int32_t y, int32_t width, int32_t height, bounds_specified specified) override
	Performs the work of setting the specified bounds of this control. More...

void	set_client_size_core (int32_t width, int32_t height) override
	Sets the size of the client area of the control. More...

virtual void	wm_mouse_double_click (message &message)
	Processes the mouse double-click message the list_box control receives from the top-level window. More...

virtual void	wm_mouse_down (message &message)
	Processes the mouse down message the list_box control receives from the top-level window. More...

virtual void	wm_mouse_up (message &message)
	Processes the mouse up message the list_box control receives from the top-level window. More...

virtual void	wm_reflect_command (message &message)
	Processes the command message the list_box control receives from the top-level window. More...

void	wnd_proc (message &message) override
	Processes Windows messages. More...

Protected Member Functions inherited from xtd::forms::list_control
	list_control ()
	Initializes a new instance of the list_control class. More...

virtual bool	allow_selection ()
	Gets a value indicating whether the list enables selection of list items. More...

virtual drawing::color	default_back_color () const override
	Gets the default background color of the control. More...

virtual drawing::color	default_fore_color () const override
	Gets the default foreground color of the control. More...

virtual void	on_selected_index_changed (const event_args &e)
	Raises the list_control::selected_index_changed event. More...

Protected Member Functions inherited from xtd::forms::control
virtual void	def_wnd_proc (message &message)
	Sends the specified message to the default window procedure. More...

bool	get_style (control_styles flag) const
	Retrieves the value of the specified control style bit for the control. More...

virtual drawing::size	measure_control () const
	Measure this control. More...

drawing::size	measure_text () const
	Measure this control text. More...

virtual void	on_auto_size_changed (const event_args &e)
	Raises the control::auto_size_changed event. More...

virtual void	on_back_color_changed (const event_args &e)
	Raises the control::back_color_changed event. More...

virtual void	on_background_image_changed (const event_args &e)
	Raises the control::background_image_changed event. More...

virtual void	on_background_image_layout_changed (const event_args &e)
	Raises the control::background_image_layout_changed event. More...

virtual void	on_click (const event_args &e)
	Raises the control::click event. More...

virtual void	on_client_size_changed (const event_args &e)
	Raises the control::client_size_changed event. More...

virtual void	on_control_added (const control_event_args &e)
	Raises the control::control_added event. More...

virtual void	on_control_removed (const control_event_args &e)
	Raises the control::control_removed event. More...

virtual void	on_create_control ()
	Raises the control::create_control event. More...

virtual void	on_cursor_changed (const event_args &e)
	Raises the control::cursor_changed event. More...

virtual void	on_dock_changed (const event_args &e)
	Raises the control::dock_changed event. More...

virtual void	on_double_click (const event_args &e)
	Raises the double_click event. More...

virtual void	on_enabled_changed (const event_args &e)
	Raises the control::enabled_changed event. More...

virtual void	on_font_changed (const event_args &e)
	Raises the control::font_changed event. More...

virtual void	on_fore_color_changed (const event_args &e)
	Raises the control::fore_color_changed event. More...

virtual void	on_got_focus (const event_args &e)
	Raises the control::got_focus event. More...

virtual void	on_handle_destroyed (const event_args &e)
	Raises the control::handle_destroyed event. More...

virtual void	on_key_down (key_event_args &e)
	Raises the control::key_down event. More...

virtual void	on_key_press (key_press_event_args &e)
	Raises the control::key_press event. More...

virtual void	on_key_up (key_event_args &e)
	Raises the control::key_up event. More...

virtual void	on_layout (const event_args &e)
	Raises the control::layout event. More...

virtual void	on_location_changed (const event_args &e)
	Raises the control::location_changed event. More...

virtual void	on_lost_focus (const event_args &e)
	Raises the control::lost_focus event. More...

virtual void	on_mouse_click (const mouse_event_args &e)
	Raises the control::mouse_click event. More...

virtual void	on_mouse_double_click (const mouse_event_args &e)
	Raises the control::mouse_double_click event. More...

virtual void	on_mouse_down (const mouse_event_args &e)
	Raises the control::mouse_down event. More...

virtual void	on_mouse_enter (const event_args &e)
	Raises the control::mouse_enter event. More...

virtual void	on_mouse_horizontal_wheel (const mouse_event_args &e)
	Raises the control::mouse_horizontal_wheel event. More...

virtual void	on_mouse_leave (const event_args &e)
	Raises the control::mouse_leave event. More...

virtual void	on_mouse_move (const mouse_event_args &e)
	Raises the control::mouse_move event. More...

virtual void	on_mouse_up (const mouse_event_args &e)
	Raises the control::mouse_up event. More...

virtual void	on_mouse_wheel (const mouse_event_args &e)
	Raises the control::mouse_wheel event. More...

virtual void	on_paint (paint_event_args &e)
	Raises the control::paint event. More...

virtual void	on_parent_back_color_changed (const event_args &e)
	Raises the control::parent_back_color_changed event. More...

virtual void	on_parent_changed (const event_args &e)
	Raises the control::parent_changed event. More...

virtual void	on_parent_cursor_changed (const event_args &e)
	Raises the control::parent_cursor_changed event. More...

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.. More...

virtual void	on_parent_font_changed (const event_args &e)
	Raises the control::parent_font_changed event. More...

virtual void	on_parent_fore_color_changed (const event_args &e)
	Raises the control::parent_fore_color_changed event. More...

virtual void	on_resize (const event_args &e)
	Raises the control::resize event. More...

virtual void	on_size_changed (const event_args &e)
	Raises the control::size_changed event. More...

virtual void	on_text_changed (const event_args &e)
	Raises the control::text_changed event. More...

virtual void	on_visible_changed (const event_args &e)
	Raises the control::visible_changed event. More...

virtual void	recreate_handle ()
	Forces the re-creation of the handle for the control. More...

void	set_style (control_styles flag, bool value)
	Sets a specified control_styles flag to either true or false. More...

Protected Member Functions inherited from xtd::forms::component
	component ()=default
	Initialises a new instance of the component class. More...

bool	design_mode () const
	Gets a value that indicates whether the component is currently in design mode. More...

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. More...

Static Public Attributes inherited from xtd::forms::list_control
static const size_t	npos
	This is a special value equal to the maximum value representable by the type size_t. More...

Static Public Member Functions inherited from xtd::forms::control
template<typename control_t >
static std::unique_ptr< control_t >	create (const control &parent, const drawing::point &location={-1, -1}, const drawing::size &size={-1, -1}, const drawing::color &back_color=drawing::color::empty, const drawing::color &fore_color=drawing::color::empty)
	A factory to create a specified control with specified parent, location ,size back_color and fore_color. More...

template<typename control_t >
static std::unique_ptr< control_t >	create (const control &parent, const xtd::ustring &text, const drawing::point &location={-1, -1}, const drawing::size &size={-1, -1}, const drawing::color &back_color=drawing::color::empty, const drawing::color &fore_color=drawing::color::empty)
	A factory to create a specified control with specified parent, text, location ,size back_color and fore_color. More...

template<typename control_t >
static std::unique_ptr< control_t >	create (const drawing::point &location={-1, -1}, const drawing::size &size={-1, -1}, const drawing::color &back_color=drawing::color::empty, const drawing::color &fore_color=drawing::color::empty)
	A factory to create a specified control with specified location ,size back_color and fore_color. More...

template<typename control_t >
static std::unique_ptr< control_t >	create (const xtd::ustring &text, const drawing::point &location={-1, -1}, const drawing::size &size={-1, -1}, const drawing::color &back_color=drawing::color::empty, const drawing::color &fore_color=drawing::color::empty)
	A factory to create a specified control with specified text, location ,size back_color and fore_color. More...

static std::optional< control_ref >	from_child_handle (intptr_t handle)
	Retrieves the control that contains the specified handle. More...

static std::optional< control_ref >	from_handle (intptr_t handle)
	Returns the control that is currently associated with the specified handle. More...

static forms::keys	modifier_keys ()
	Gets a value indicating which of the modifier keys (SHIFT, CTRL, and ALT) is in a pressed state. More...

static forms::mouse_buttons	mouse_buttons ()
	Gets a value indicating which of the mouse buttons is in a pressed state. More...

Static Public Member Functions inherited from xtd::object
static bool	equals (const object &object_a, const object &object_b) noexcept
	Determines whether the specified object instances are considered equal. More...

static bool	reference_equals (const object &object_a, const object &object_b) noexcept
	Determines whether the specified object instances are the same instance. More...

Constructor & Destructor Documentation

◆ combo_box()

xtd::forms::combo_box::combo_box ( )

Initializes a new instance of the combo_box class.

Member Function Documentation

◆ 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.

◆ create_params()

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

overrideprotectedvirtual

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.

◆ default_size()

virtual drawing::size xtd::forms::combo_box::default_size ( ) const

inlineoverridevirtual

Gets the default size of the control.

Returns: The default size of the control.

Reimplemented from xtd::forms::control.

◆ drop_down_style() [1/2]

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

inline

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.

◆ 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.

◆ 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.

◆ items() [1/3]

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

inline

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.

◆ items() [2/3]

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

inline

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 )

inline

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.

◆ on_drop_down_style_changed()

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

protectedvirtual

Raises the combo_box::drop_down_style_changed event.

◆ on_handle_created()

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

overrideprotectedvirtual

Raises the 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.

◆ selected_index() [1/3]

virtual size_t xtd::forms::list_control::selected_index

inline

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.

◆ selected_index() [2/3]

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.

◆ selected_index() [3/3]

virtual list_control& xtd::forms::list_control::selected_index

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.

◆ selected_item() [1/2]

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

inline

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.

◆ set_bounds_core()

void xtd::forms::combo_box::set_bounds_core	(	int32_t	x,
		int32_t	y,
		int32_t	width,
		int32_t	height,
		bounds_specified	specified
	)

overrideprotectedvirtual

Performs the work of setting the specified bounds of this control.

Parameters

x	The new left property value of the control.
y	The new top property value of the control.
width	The new width property value of the control.
height	The new height property value of the control.
specified	A bitwise combination of the bounds_specified values.

Remarks: Typically, the parameters that correspond to the bounds not included in the specified parameter are passed in with their current values. For example, the height, width, or the y or y properties of the location property can be passed in with a reference to the current instance of the control. However all values passed in are honored and applied to the control.; The specified parameter represents the elements of the controls Bounds changed by your application. For example, if you change the size of the control, the specified parameter value is the size value of bounds_specified. However, if the size is adjusted in response to the dock property being set, the specified parameter value is the none value of bounds_specified.

Notes to Inheritors: When overriding set_bounds_core(int32_t, int32_t, int32_t, int32_t, bounds_specified) in a derived class, be sure to call the base class's set_bounds_core(int32_t, int32_t, int32_t, int32_t, bounds_specified) method to force the bounds of the control to change. Derived classes can add size restrictions to the set_bounds_core(int32_t, int32_t, int32_t, int32_t, bounds_specified) method.

Reimplemented from xtd::forms::control.

◆ set_client_size_core()

void xtd::forms::combo_box::set_client_size_core	(	int32_t	width,
		int32_t	height
	)

overrideprotectedvirtual

Sets the size of the client area of the control.

Parameters

width	The client area width, in pixels.
height	The client area height, in pixels.

Remarks: The client area starts at the (0, 0) location and extends to the (width, height) location.; Typically, you should not set the client_size of the control.

Notes to Inheritors: When overriding set_client_size_core(int32_t, int32_t) in a derived class, be sure to call the base class's set_client_size_core(int32_t, int32_t) method so that the client_size property is adjusted.

Reimplemented from xtd::forms::control.

◆ sorted() [1/2]

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

inlinevirtual

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::ustring & text )

inlineoverridevirtual

Sets the text associated with this control.

Parameters

text	The text associated with this control.

Reimplemented from xtd::forms::control.

◆ wm_mouse_double_click()

virtual void xtd::forms::combo_box::wm_mouse_double_click ( message & message )

protectedvirtual

Processes the mouse double-click message the list_box control receives from the top-level window.

Parameters

message The message the top-level window sent to the list_box control.

◆ wm_mouse_down()

virtual void xtd::forms::combo_box::wm_mouse_down ( message & message )

protectedvirtual

Processes the mouse down message the list_box control receives from the top-level window.

Parameters

message The message the top-level window sent to the list_box control.

◆ wm_mouse_up()

virtual void xtd::forms::combo_box::wm_mouse_up ( message & message )

protectedvirtual

Processes the mouse up message the list_box control receives from the top-level window.

Parameters

message The message the top-level window sent to the list_box control.

◆ wm_reflect_command()

virtual void xtd::forms::combo_box::wm_reflect_command ( message & message )

protectedvirtual

Processes the command message the list_box control receives from the top-level window.

Parameters

message The message the top-level window sent to the list_box 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.

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

xtd.forms/include/xtd/forms/combo_box.h

Definition

Public Attributes

Public Member Functions

Protected Member Functions

Additional Inherited Members

Constructor & Destructor Documentation

◆ combo_box()

Member Function Documentation

◆ begin_update()

◆ create_params()

◆ default_size()

◆ drop_down_style() [1/2]

◆ drop_down_style() [2/2]

◆ end_update()

◆ items() [1/3]

◆ items() [2/3]

◆ items() [3/3]

◆ on_drop_down_style_changed()

◆ on_handle_created()

◆ on_selected_value_changed()

◆ selected_index() [1/3]

◆ selected_index() [2/3]

◆ selected_index() [3/3]

◆ selected_item() [1/2]

◆ selected_item() [2/2]

◆ set_bounds_core()

◆ set_client_size_core()

◆ sorted() [1/2]

◆ sorted() [2/2]

◆ text()

◆ wm_mouse_double_click()

◆ wm_mouse_down()

◆ wm_mouse_up()

◆ wm_reflect_command()

◆ wnd_proc()