using System.Drawing;

using System.Windows.Forms;

​

// Get the bounds of the primary screen

Rectangle screenBounds = Screen.PrimaryScreen.Bounds;

​

// Create a bitmap object to hold the screenshot

Bitmap screenshot = new Bitmap(screenBounds.Width, screenBounds.Height);

​

// Create a graphics object from the bitmap

using (Graphics graphics = Graphics.FromImage(screenshot))

{

    // Capture the screen and draw it onto the graphics object

    graphics.CopyFromScreen(screenBounds.X, screenBounds.Y, 0, 0, screenBounds.Size);

}

​

// Save the screenshot as a PNG file

screenshot.Save("screenshot.png", System.Drawing.Imaging.ImageFormat.Png);

​