SetLayeredWindowAttributes.md

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Function name : SetLayeredWindowAttributes

Group: Window - Library: user32

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The SetLayeredWindowAttributes function sets the opacity and transparency color key of a layered window.

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Code examples:

Creating irregularly shaped FoxPro form using transparency color key
Semi-transparent Form
Transparent Menu Class (requires VFP9)
Placing On-screen Alert on top of all windows
How to make a VFP form fading out when released (GDI+ version)
How to make a VFP form fading out when released (GDI version)
Displaying dimmed window behind VFP top-level form

Declaration:

BOOL SetLayeredWindowAttributes(
    HWND hwnd,
    COLORREF crKey,
    BYTE bAlpha,
    DWORD dwFlags
);  

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FoxPro declaration:

DECLARE INTEGER SetLayeredWindowAttributes IN user32;
	INTEGER hwnd,;
	INTEGER crKey,;
	SHORT   bAlpha,;
	INTEGER dwFlags
  

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Parameters:

hwnd [in] Handle to the layered window.

crKey [in] COLORREF structure that specifies the transparency color key to be used when composing the layered window.

bAlpha [in] Alpha value used to describe the opacity of the layered window.

dwFlags [in] Specifies an action to take: LWA_COLORKEY, LWA_ALPHA

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Return value:

If the function succeeds, the return value is nonzero.

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Comments:

A layered window is created by specifying WS_EX_LAYERED when creating the window with the CreateWindowEx function or by setting WS_EX_LAYERED via SetWindowLong after the window has been created.

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