PrintWindow截取隐藏窗口

PrintWindow的好处就在这，只要想截的窗口不是最小化，无论在屏幕外还是只显示一半还是被覆盖，都可以成功截取我们想要的部分。

C#代码如下：(网上代码有些缺陷，略做修改)

        public static Bitmap GetWindow(IntPtr hWnd)    //hWnd可以是窗口、控件等的handle，因此这种方法截我们想要的部分非常好用。
        {      
              IntPtr hscrdc = GetWindowDC(hWnd);
              Control control = Control.FromHandle(hWnd);
              IntPtr hbitmap = CreateCompatibleBitmap(hscrdc, control.Width, control.Height);
              IntPtr hmemdc = CreateCompatibleDC(hscrdc);
              SelectObject(hmemdc, hbitmap);
              bool re= PrintWindow(hWnd, hmemdc, 0);
              Bitmap bmp = null;
              if(re)
              {
                 bmp = Bitmap.FromHbitmap(hbitmap);                  
              }
              DeleteObject(hbitmap);
              DeleteDC(hmemdc);//删除用过的对象       
              ReleaseDC(hWnd, hscrdc);
              return bmp;
        }

调用非托管函数如下：

        [DllImport("gdi32.dll")]
        public static extern IntPtr CreateDC(
        string lpszDriver, // driver name驱动名
        string lpszDevice, // device name设备名
        string lpszOutput, // not used; should be NULL
        IntPtr lpInitData // optional printer data
        );

        [DllImport("gdi32.dll")]
        public static extern IntPtr CreateCompatibleDC(IntPtr hdc);    // handle to DC

        [DllImport("gdi32.dll")]
        public static extern IntPtr CreateCompatibleBitmap(
        IntPtr hdc, // handle to DC
        int nWidth, // width of bitmap, in pixels
        int nHeight // height of bitmap, in pixels
        );

        [DllImport("gdi32.dll")]
        public static extern IntPtr SelectObject(
        IntPtr hdc, // handle to DC
        IntPtr hgdiobj // handle to object
        );

        [DllImport("gdi32.dll")]
        public static extern int DeleteDC( IntPtr hdc );   // handle to DC
       

        [DllImport("gdi32.dll")]
        public static extern IntPtr DeleteObject(IntPtr hObject);

        [DllImport("user32.dll")]
        public static extern bool PrintWindow(
        IntPtr hwnd, // Window to copy,Handle to the window that will be copied. 
        IntPtr hdcBlt, // HDC to print into,Handle to the device context. 
        UInt32 nFlags // Optional flags,Specifies the drawing options. It can be one of the following values. 
        );

        [DllImport("user32.dll")]
        public static extern IntPtr GetWindowDC( IntPtr hwnd );

        [DllImport("user32.dll")]
        public static extern IntPtr ReleaseDC(IntPtr hWnd, IntPtr hDC);

附：有些平台的截图是全黑的，开启视频加速可能会导致这样的问题，关闭就能正常截图了。