For a basic personal interest project, I'm trying to make a C# winform which is a screen capture device, I want to be able to resize a transparent window, press a button on keyboard and the program save what it can see transparently through itself to a file.
All I need help with is a non-hacky way to get the image of what can be seen through the transparent window.
A quick mock up in ms paint: Mock up image
Any help would be appreciated.