The MSG structure contains message information from a thread's message queue.

MSG Structure definition:

typedef struct tagMSG {
    HWND   hwnd;     
    UINT   message; 
    WPARAM wParam; 
    LPARAM lParam; 
    DWORD  time; 
    POINT  pt; 
} MSG;

Members and their description:

  • hwnd - Handle to the window whose window procedure receives the message.
  • message - Specifies the message number.
  • wParam - Specifies additional information about the message. The exact meaning depends on the value of the message member.
  • lParam - Specifies additional information about the message. The exact meaning depends on the value of the message member.
  • time - Specifies the time at which the message was posted.
  • pt -Specifies the cursor position, in screen coordinates, when the message was posted.

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