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ON_MESSAGE

Indicates which function will handle a user-defined message.

ON_MESSAGE(message, memberFxn )

Parameters

message
The message ID.
memberFxn
The name of the message-handler function to which the message is mapped.

Remarks

User-defined messages are usually defined in the range WM_USER to 0x7FFF. User-defined messages are any messages that are not standard Windows WM_MESSAGE messages. There should be exactly one ON_MESSAGE macro statement in your message map for every user-defined message that must be mapped to a message-handler function.

Note   In addition to user-defined messages, ON_MESSAGE handles less common Windows messages. For more information, see the Knowledge Base article Q99848.

For more information and examples, see Message Handling and Mapping Topics.

Example

// example for ON_MESSAGE
#define WM_MYMESSAGE (WM_USER + 1)
BEGIN_MESSAGE_MAP( CMyWnd, CMyParentWndClass )
    ON_MESSAGE( WM_MYMESSAGE, OnMyMessage )
    // ... Possibly more entries to handle additional messages
END_MESSAGE_MAP( )

See Also

MFC Macros and Globals | ON_UPDATE_COMMAND_UI | ON_CONTROL | ON_REGISTERED_MESSAGE | ON_COMMAND | User-Defined Handlers

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