WM_ACTIVATE

This message is sent when a window is being activated or deactivated. This message is sent first to the window procedure of the top-level window being deactivated; it is then sent to the window procedure of the top-level window being activated.

WM_ACTIVATE fActive = LOWORD(wParam); 
fMinimized = (BOOL)HIWORD(wParam);
hwndPrevious = (HWND) lParam;

Parameters

  • fActive
    Value of the low-order word of wParam. Specifies whether the window is being activated or deactivated. It is one of the following values:

    Value Description
    WA_ACTIVE Activated by some method other than a mouse click (for example, by a call to the SetActiveWindow function or by use of the keyboard interface to select the window).
    WA_CLICKACTIVE Activated by a mouse click
    WA_INACTIVE Deactivated
  • fMinimized
    Value of the high-order word of wParam. Specifies the minimized state of the window being activated or deactivated. A nonzero value indicates the window is minimized.

  • hwndPrevious
    Handle to the window being activated or deactivated, depending on the value of the fActive parameter. If the value of fActive is WA_INACTIVE, hwndPrevious is the handle to the window being activated. If the value of fActive is WA_ACTIVE or WA_CLICKACTIVE, hwndPrevious is the handle to the window being deactivated. This handle can be NULL, and is always NULL when the window being activated and the window being deactivated are in separate processes.

Return Values

An application should return zero if it processes this message.

  • Default Action
    If the window is being activated and is not minimized, the DefWindowProc function sets the keyboard focus to the window.

Remarks

The fMinimized parameter must be zero.

If the window is activated by a mouse click, it also receives a WM_MOUSEACTIVATE message.

Requirements

Runs on Versions Defined in Include Link to
Windows CE OS 1.0 and later Winuser.h    

Note   This API is part of the complete Windows CE OS package as provided by Microsoft. The functionality of a particular platform is determined by the original equipment manufacturer (OEM) and some devices may not support this API.

See Also

DefWindowProc, SetActiveWindow

 Last updated on Tuesday, July 13, 2004

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