[c#] Capture the screen shot using .NET

Possible Duplicate:
How May I Capture the Screen in a Bitmap?

I need to make an application that captures a snapshot of the current screen whenever a particular button is hit.

I have searched a lot, but I have only found how to capture the current window.

Can you please help me figure out how to do this in .NET?

We can do this manually by hitting print-screen and saving the image using the paint. I need to do the same thing, but I want to do so with a program.

It's certainly possible to grab a screenshot using the .NET Framework. The simplest way is to create a new Bitmap object and draw into that using the Graphics.CopyFromScreen method.

Sample code:

using (Bitmap bmpScreenCapture = new Bitmap(Screen.PrimaryScreen.Bounds.Width, 
                                            Screen.PrimaryScreen.Bounds.Height))
using (Graphics g = Graphics.FromImage(bmpScreenCapture))
{
    g.CopyFromScreen(Screen.PrimaryScreen.Bounds.X,
                     Screen.PrimaryScreen.Bounds.Y,
                     0, 0,
                     bmpScreenCapture.Size,
                     CopyPixelOperation.SourceCopy);
}

Caveat: This method doesn't work properly for layered windows. Hans Passant's answer here explains the more complicated method required to get those in your screen shots.