/// CaptureScreen是完成屏幕截取的类

    public class CaptureScreen

    {

        #region Public Class Functions

        public static Bitmap GetDesktopImage()

        {

            IntPtr m_HBitmap;

            System.Drawing.Bitmap bmp=null;

            SIZE size;

            IntPtr   hDC = PlatformInvokeUSER32.GetDC(PlatformInvokeUSER32.GetDesktopWindow());

            IntPtr hMemDC = PlatformInvokeGDI32.CreateCompatibleDC(hDC);

            size.cx = PlatformInvokeUSER32.GetSystemMetrics                (PlatformInvokeUSER32.SM_CXSCREEN);

                    size.cy = PlatformInvokeUSER32.GetSystemMetrics(PlatformInvokeUSER32.SM_CYSCREEN);

            m_HBitmap = PlatformInvokeGDI32.CreateCompatibleBitmap(hDC, size.cx, size.cy);

            if (m_HBitmap!=IntPtr.Zero)

            {

                                IntPtr hOld = (IntPtr) PlatformInvokeGDI32.SelectObject(hMemDC,  m_HBitmap);

                PlatformInvokeGDI32.BitBlt(hMemDC, 0, 0,size.cx,size.cy, hDC, 0, 0,PlatformInvokeGDI32.SRCCOPY);

                PlatformInvokeGDI32.SelectObject(hMemDC, hOld);

                PlatformInvokeGDI32.DeleteDC(hMemDC);

                PlatformInvokeUSER32.ReleaseDC(PlatformInvokeUSER32.GetDesktopWindow(), hDC);

                bmp=System.Drawing.Image.FromHbitmap(m_HBitmap);

                PlatformInvokeGDI32.DeleteObject(m_HBitmap);

                return bmp;

            }

            return null;

        }

        #endregion

    }

    //该结构控制截取屏幕的大小

    public struct SIZE

    {

        public int cx;

        public int cy;

    }

}

这样就可以效果很好地实现C#屏幕截取编程了。

5 总结

C#屏幕截取编程需要使用很多API编程，使用单独封装的cs文件，即可采用“分而治之”的策略降低编程难度。