GetMessage function

Namespace: Winuser.h

Header: Windows.h

Library: User32.lib

Syntax

BOOL GetMessage(
    LPMSG lpMsg,
    HWND  hWnd,
    UINT  wMsgFilterMin,
    UINT  wMsgFilterMax
);

Parameters

Parameter	Type	Description
lpMsg	LPMSG	Pointer to an `MSG` structure that receives message information.
hWnd	HWND	Handle to the window whose messages are to be retrieved. If `NULL`, messages for any window belonging to the current thread are retrieved.
wMsgFilterMin	UINT	Smallest value of the range of message identifiers to be retrieved. If both filter parameters are zero, no filtering is performed.
wMsgFilterMax	UINT	Largest value of the range of message identifiers to be retrieved.

Return Value

Returns non‑zero if a message other than WM_QUIT is retrieved; zero if the message is WM_QUIT; and -1 on error. Call GetLastError for extended error information when -1 is returned.

Remarks

GetMessage removes the retrieved message from the thread's message queue.

Typical message loop:

MSG msg;
while (GetMessage(&msg, NULL, 0, 0)) {
    TranslateMessage(&msg);
    DispatchMessage(&msg);
}

Use PeekMessage for non‑blocking retrieval.
The function blocks until a message is available unless the thread has no messages and a WM_QUIT message is posted.

Requirements

Client: Windows 2000 or later.
Header: Windows.h (includes Winuser.h)
Library: User32.lib

Microsoft Docs – Windows API Reference