xtd::forms::message Class Reference

#include <message.h>

Definition

Implements a Windows 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.

Inherits xtd::object.

Public Member Functions
template<typename type >
type	get_lparam ()
	Gets the lparam value and converts the value to an object.
intptr_t	hwnd () const
	Gets the window handle of the message.
void	hwnd (intptr_t value)
	Sets the window handle of the message.
intptr_t	lparam () const
	Gets the lparam field of the message.
void	lparam (intptr_t value)
	Sets the lparam field of the message.
int32_t	msg () const
	Gets the ID number for the message.
void	msg (int32_t value)
	Sets the ID number for the message.
intptr_t	result () const
	Gets the value that is returned to Windows in response to handling the message.
void	result (intptr_t value)
	Sets the value that is returned to Windows in response to handling the message.
xtd::ustring	to_string () const noexcept override
	Returns a string that represents the current message.
intptr_t	wparam () const
	Gets the wparam field of the message.
void	wparam (intptr_t value)
	Sets the wparam field of the message.
Public Member Functions inherited from xtd::object
	object ()=default
	Create a new instance of the ultimate base class object.
virtual bool	equals (const object &obj) const noexcept
	Determines whether the specified object is equal to the current object.
virtual size_t	get_hash_code () const noexcept
	Serves as a hash function for a particular type.
template<typename object_t >
std::unique_ptr< object_t >	memberwise_clone () const
	Gets the type of the current instance.
virtual xtd::ustring	to_string () const noexcept
	Returns a std::string that represents the current object.

Static Public Member Functions
static message	create (intptr_t hwnd, int32_t msg, intptr_t wparam, intptr_t lparam)
	Creates a new message.
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.
static bool	reference_equals (const object &object_a, const object &object_b) noexcept
	Determines whether the specified object instances are the same instance.

Member Function Documentation

create()

static message xtd::forms::message::create ( intptr_t  hwnd, int32_t  msg, intptr_t  wparam, intptr_t  lparam  )

inlinestatic

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.

get_lparam()

template<typename type >

type xtd::forms::message::get_lparam ( )

inline

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.

hwnd() [1/2]

intptr_t xtd::forms::message::hwnd ( ) const

inline

Gets the window handle of the message.

Returns

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.

hwnd() [2/2]

void xtd::forms::message::hwnd ( intptr_t  value )

inline

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.

lparam() [1/2]

intptr_t xtd::forms::message::lparam ( ) const

inline

Gets the lparam field of the message.

Returns

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.

lparam() [2/2]

void xtd::forms::message::lparam ( intptr_t  value )

inline

Sets the lparam field of the message.

Parameters

value

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.

msg() [1/2]

int32_t xtd::forms::message::msg ( ) const

inline

Gets the ID number for the message.

Returns

The ID number for the message.

msg() [2/2]

void xtd::forms::message::msg ( int32_t  value )

inline

Sets the ID number for the message.

Parameters

value

The ID number for the message.

result() [1/2]

intptr_t xtd::forms::message::result ( ) const

inline

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

Returns

The return value of the message.

result() [2/2]

void xtd::forms::message::result ( intptr_t  value )

inline

Sets the value that is returned to Windows in response to handling the message.

Parameters

value

The return value of the message.

to_string()

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

overridevirtualnoexcept

Returns a string that represents the current message.

Returns

A xtd::ustring that represents the current message.

Reimplemented from xtd::object.

wparam() [1/2]

intptr_t xtd::forms::message::wparam ( ) const

inline

Gets the wparam field of the message.

Returns

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.

wparam() [2/2]

void xtd::forms::message::wparam ( intptr_t  value )

inline

Sets the wparam field of the message.

Parameters

value

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.

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

• xtd.forms/include/xtd/forms/message.h