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 WM_ACTIVATE

The WM_ACTIVATE message is sent to both the window being activated and the window being deactivated. If the windows use the same input queue, the message is sent synchronously, first to the window procedure of the top-level window being deactivated, then to the window procedure of the top-level window being activated. If the windows use different input queues, the message is sent asynchronously, so the window is activated immediately.

Parameters

• wParam
The low-order word specifies whether the window is being activated or deactivated. This parameter can be one of the following values. The high-order word specifies the minimized state of the window being activated or deactivated. A nonzero value indicates the window is minimized.
• 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.
• lParam
Handle to the window being activated or deactivated, depending on the value of the wParam parameter. If the low-order word of wParam is WA_INACTIVE, lParam is the handle to the window being activated. If the low-order word of wParam is WA_ACTIVE or WA_CLICKACTIVE, lParam is the handle to the window being deactivated. This handle can be NULL.

Return Value

If an application processes this message, it should return zero.

Remarks

If the window is being activated and is not minimized, the DefWindowProc function sets the keyboard focus to the window. If the window is activated by a mouse click, it also receives a WM_MOUSEACTIVATE message.

Notification Requirements

• Minimum DLL Version None
• Header Declared in Winuser.h, include Windows.h
• Minimum operating systems Windows 95, Windows NT 3.1

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Notebook exported on Monday, 7 July 2008, 18:56:50 PM Eastern Daylight Time