I need to capture a screenshot of the scrolling window\'s client area, using .NET. My first priority is capturing web page screenshots. But this can be not the only one use
I've continued my search and founded IECapt, — an open source tool which can take a web page screenshot using IE inside of it. It has С++ and .NET versions. Also there are Qt/WebKit-based analog from the same author: http://cutycapt.sourceforge.net.
This tools is not a direct answer for my question, but both of them solve the original problem by 90%.