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.

  The type of the function must be afx_msg LRESULT (CWnd::*)(WPARAM, LPARAM).

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.

For more information and examples, see Message Handling and Mapping Topics and User-Defined Handlers

Example

#define WM_MYMESSAGE (WM_USER + 100)

BEGIN_MESSAGE_MAP(CMyWnd2, CWnd)
   ON_MESSAGE(WM_MYMESSAGE, OnMyMessage)
END_MESSAGE_MAP()

LRESULT CMyWnd2::OnMyMessage(WPARAM wParam, LPARAM lParam)
{
   UNREFERENCED_PARAMETER(wParam);
   UNREFERENCED_PARAMETER(lParam);

   // Handle message here.

   return 0;
}

Requirements

Header: afxmsg_.h

See Also

Concepts

MFC Macros and Globals

ON_UPDATE_COMMAND_UI

ON_CONTROL

ON_REGISTERED_MESSAGE

ON_COMMAND