c#截取屏幕的几种方法~

1：

private void button1_Click(object sender, EventArgs e)
        {
            Bitmap bit =new Bitmap (Screen.AllScreens[0].Bounds.Width ,Screen.AllScreens[0].Bounds.Height);
               Graphics g1 = Graphics.FromImage(bit);
            g1.CopyFromScreen(new Point(0, 0), new Point(0, 0), bit.Size);
            this.BackgroundImage =(Image)bit;
        }

 

 

2：

[DllImport("user32", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]
        private static extern IntPtr GetDC(IntPtr hWnd);
        [DllImport("GDI32", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]
        private static extern int BitBlt(IntPtr srchDC, int srcX, int srcY, int srcW, int srcH, IntPtr desthDC, int destX, int destY, int op);
        [System.Runtime.InteropServices.DllImportAttribute("gdi32.dll")]
        private static extern IntPtr CreateDC(
        string lpszDriver, // 驱动名称
        string lpszDevice, // 设备名称
        string lpszOutput, // 无用，可以设定位"NULL"
        IntPtr lpInitData // 任意的打印机数据
        );

        private void button1_Click(object sender, EventArgs e)
        {
           
            IntPtr dc1 = CreateDC("DISPLAY", null, null, (IntPtr)null);
            //由一个指定设备的句柄创建一个新的Graphics对象
            Graphics g1 = Graphics.FromHdc(dc1);
            Image ScreenImage = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height, g1);
            //根据屏幕大小创建一个与之相同大小的Bitmap对象
            Graphics g2 = Graphics.FromImage(ScreenImage);
            IntPtr dc3 = g1.GetHdc();                     //获得屏幕的句柄
            IntPtr dc2 = g2.GetHdc();                     //获得位图的句柄
            BitBlt(dc2, 0, 0, Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height, dc3, 0, 0, 0xcc0020);//把当前屏幕拷贝到位图中
            g1.ReleaseHdc(dc3);//释放屏幕句柄
            g2.ReleaseHdc(dc2);//释放位图句柄
            this.BackgroundImage = ScreenImage;
        }