Question regards to the Windows 7 screen capture.

namespace System.Drawing
{
    using System;
    using System.Runtime.InteropServices;

    public static class ScreenCapture
    {
        public static Bitmap DesktopCapture()
        {
            Bitmap bitmap;
            IntPtr desktopWindow = GetDesktopWindow();
            IntPtr dC = GetDC(desktopWindow);
            try
            {
                bitmap = Image.FromHbitmap(GetCurrentObject(dC, 7));
            }
            finally
            {
                ReleaseDC(desktopWindow, dC);
            }
            return bitmap;
        }

        [DllImport("gdi32.dll")]
        private static extern IntPtr GetCurrentObject(IntPtr hdc, ushort objectType);
        [DllImport("user32.dll")]
        private static extern IntPtr GetDC(IntPtr hwnd);
        [DllImport("User32")]
        private static extern IntPtr GetDesktopWindow();
        [DllImport("user32.dll")]
        private static extern void ReleaseDC(IntPtr hwnd, IntPtr hdc);
    }
}