About the display of transparent windows

1th Kind

Translucent window

//----------------------------------------------------------------
void __fastcall TForm1::FormCreate(TObject *Sender)
{
　 long lRt=GetWindowLong(Handle,GWL_EXSTYLE);
　 lRt=lRt|WS_EX_LAYERED;
　 SetWindowLong(Handle,GWL_EXSTYLE,lRt);
　 SetLayeredWindowAttributes(Handle,clBlue,200,LWA_ALPHA);
}
//-----------------------------------------------------------------

2nd Kind

I have long wanted to write a piece of my experience, has been very busy not empty, but this call me, it is not good again fainthearted.

In fact, I also have a lot of problems have not been resolved, here also to master advice.

This article in V-galaxy BBS published, if you want to paste, please contact the author info@ministars.com

1. Windows 2000 's GDI + expansion set

Windows 2000 internally expands the original GDI instruction set, providing efficient image processing instructions such as alpha blending. There is a special window style in Win2000 that ws_ex_layered provide a transparent window. WIN2000 also offers such as AnimateWindow (...) A class of APIs that directly support window animations.

About connections

Http://www.microsoft.com/hwdev/video/GDInext.htm

http://x.wonder.ca/stevex/nthack/

2. The implementation method under Win95/nt

Since Windows doesn't offer ready-made, it has to do it by itself. In principle this is the process:

A. Get the desktop DC, generate a compatible bitmap, send a WM_PAINT message, and take the desktop to bitmap. (Just like a screen Capture)

B. Draw the window you want to open to another picture bitmap

C. Use these two pictures to do alpha blending, or other effects, to generate a third picture.

D. Finally bitblt the picture out