How can I produce an OSD in Windows?

I want to create an on-screen display, i.e. text or simple graphics that appear on top of everything else being displayed. I know in Linux this is achieved with xosd, but how do you do it in Windows? (Assume XP and up if it makes it easier, and I would also be interested in kno开发者_运维知识库wing if the method is different in Vista/7)

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You can use NativeWindow to do this as described here.

The article explains how to create an OSD window with animation/semi-transparent effects, in C#, using the NativeWindow class.

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Use the WS_EX_LAYERED style to make the window transparent, and SetWindowPos(..., HWND_TOPMOST, ...) to make it float above other windows.

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You can call SetForeGroundWindow