How Can I intercept high level GDI draw commands ?

Question

Hello guys,

I'm trying to make a application that allows remote access to other applications (running on different machines). The idea is to make give users transparent accesso to certain applications, I've basically two options:

• Application Streaming
• Intercepting draw command and reproduce them in the client

(of course, the input is redirected from the client to the server)

I've a working version with application streaming, but I don't have a clue of how to do it through hooking in the Win API...

Any ideas ?

Answer 1

What you're describing sounds a lot like a Windows metafile. The metafile captures all GDI drawing commands to a file; that file can then be passed to a remote PC and rendered there.

See CreateEnhMetaFile for starters. This returns a handle to a device context, which you draw to instead of drawing to the normal screen device context.