xtd::forms::message Struct Reference

Inheritance diagram for xtd::forms::message:

Definition

Implements a Windows message.

Header

#include <xtd/forms/message>

Namespace

xtd::forms

Library

xtd.forms

Remarks

The message structure wraps messages that Windows sends. You can use this structure to wrap a message and assign it to the window procedure to be dispatched. You can also use this structure to get information about a message the system sends to your application or controls.

You cannot create the message directly. Instead, use the create method. For the sake of efficiency, the message uses its pool of existing Messages instead of instantiating a new one, if possible. However, if a message is not available in the pool, a new one is instantiated.

Windows message are simulate on macOS and linux.

Examples

action1.cpp, action2.cpp, action3.cpp, application_add_message_filter.cpp, form_and_messages.cpp, and wnd_proc.cpp.

Public Properties
intptr	hwnd
	Gets or sets the window handle of the message.
uint32	msg
	Gets or sets the ID number for the message.
intptr	wparam
	Gets or sets the wparam field of the message.
intptr	lparam
	Sets the lparam field of the message.
intptr	result
	Gets or sets the value that is returned to Windows in response to handling the message.
intptr	__handle__
	Gets or sets the handle field of the message.

Public Methods
bool	equals (const xtd::object &obj) const noexcept override
	Determines whether the specified object is equal to the current object.
bool	equals (const message &other) const noexcept override
	Determines whether the specified object is equal to the current object.
xtd::size	get_hash_code () const noexcept override
	Serves as a hash function for a particular type.
template<class type_t >
type_t	get_lparam () const noexcept
	Gets the lparam value and converts the value to an object.
xtd::string	to_msg_string () const noexcept
	Returns a string that represents the msg property.
xtd::string	to_string () const noexcept override
	Returns a string that represents the current message.

Public Static Methods
static message	create (intptr hwnd, int32 msg, intptr wparam, intptr lparam)
	Creates a new message.

Additional Inherited Members
Public Member Functions inherited from xtd::object
	object ()=default
	Create a new instance of the ultimate base class object.
virtual type_object	get_type () const noexcept
	Gets the type of the current instance.
template<class object_t >
xtd::uptr< object_t >	memberwise_clone () const
	Creates a shallow copy of the current object.
Public Member Functions inherited from xtd::iequatable< message >
virtual bool	equals (const message &) const noexcept=0
	Indicates whether the current object is equal to another object of the same type.
Static Public Member Functions inherited from xtd::object
template<class object_a_t , class 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<class object_a_t , class 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.

Member Function Documentation

equals() [1/2]

bool xtd::forms::message::equals ( const xtd::object &  obj ) const

overridevirtualnoexcept

Determines whether the specified object is equal to the current object.

Parameters

obj	The object to compare with the current object.

Returns

true if the specified object is equal to the current object. otherwise, false.

Reimplemented from xtd::object.

equals() [2/2]

bool xtd::forms::message::equals ( const message &  other ) const

overridenoexcept

Determines whether the specified object is equal to the current object.

Parameters

other

The object to compare with the current object.

Returns

true if the specified object is equal to the current object. otherwise, false.

get_hash_code()

xtd::size xtd::forms::message::get_hash_code ( ) const

overridevirtualnoexcept

Serves as a hash function for a particular type.

Returns

A hash code for the current object.

Reimplemented from xtd::object.

get_lparam()

template<class type_t >

type_t xtd::forms::message::get_lparam ( ) const

inlinenoexcept

Gets the lparam value and converts the value to an object.

Template Parameters

type	The type to use to create an instance. This type must be declared as a structure type.

Returns

An object that represents an instance of the class specified by the template parameter, with the data from the lparam field of the message.

to_msg_string()

xtd::string xtd::forms::message::to_msg_string ( ) const

noexcept

Returns a string that represents the msg property.

Returns

A xtd::string that represents the msg property.

to_string()

xtd::string xtd::forms::message::to_string ( ) const

overridevirtualnoexcept

Returns a string that represents the current message.

Returns

A xtd::string that represents the current message.

Reimplemented from xtd::object.

create()

static message xtd::forms::message::create ( intptr  hwnd, int32  msg, intptr  wparam, intptr  lparam  )

static

Creates a new message.

Parameters

hwnd	The window handle that the message is for.
msg	The message ID.The message ID.
wparam	The message wparam field.
lparam	The message lparam field.

Returns

A xtd::forms::message that represents the message that was created.

Remarks

Use the xtd::message::create method to create a xtd::forms::message to wrap a message sent by Windows.

Member Data Documentation

hwnd

intptr xtd::forms::message::hwnd

Gets or sets the window handle of the message.

Parameters

hwnd	The window handle of the message.

Remarks

Window handle is a value that uniquely identifies a window on the system. This property returns a handle of the window whose window procedure receives this message. It is useful when your code need to interact with some native Windows API functions that expect window handles as parameters.

Examples

application_add_message_filter.cpp.

msg

uint32 xtd::forms::message::msg

Gets or sets the ID number for the message.

Parameters

msg	The ID number for the message.

Examples

application_add_message_filter.cpp, and form_and_messages.cpp.

wparam

intptr xtd::forms::message::wparam

Gets or sets the wparam field of the message.

Parameters

wparam

The wparam field of the message.

Remarks

The value of this field depends on the message. Use the wparam field to get information that is important to handling the message. This field is typically used to store small pieces of information, such as flags.

Examples

form_and_messages.cpp.

lparam

intptr xtd::forms::message::lparam

Sets the lparam field of the message.

Parameters

lparam

The lparam field of the message.

Remarks

The value of this field depends on the message. Use the lparam field to get information that is important for handling the message. lparam is typically used to store an object if it is needed by the message.

Examples

form_and_messages.cpp.

result

intptr xtd::forms::message::result

Gets or sets the value that is returned to Windows in response to handling the message.

Parameters

result

The return value of the message.

__handle__

intptr xtd::forms::message::__handle__

Gets or sets the handle field of the message.

Parameters

handle

The handle field of the message.

Warning

Internal use only

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

• xtd.forms/include/xtd/forms/message.hpp