How can I get functionality similar to Spy++ in my C# app?

Question

I\'m interested in working on a plugin for Keepass, the open-source password manager. Right now, Keepass currently detects what password to copy/paste for you based off of

Answer 1

For the functionality of pointing to a window. You need to SetCapture() so that you get mouse messages that are outside of your window. Then use WindowFromPoint() to convert a mouse position to a Window. You will need to convert the moust position from client coordinates to window coordinates first.

If you try an call SetCapture() anywhere but on a mouse click message, you will probably be ignored. This is the reason that Spy++ makes you click on an Icon and drag and drop it on the window you want to point to.