C# 非顶端窗口截图 - 用于查找指定窗口并截图

panel上可以通过DrawToBitmap截图，不管是否在屏幕外是否有遮挡         

 Bitmap sourceBitmap = new Bitmap(400, 300);

            //Control ct = frmMain.mianForm.panel1 as Control;

            //ct.DrawToBitmap(sourceBitmap, new System.Drawing.Rectangle(0, 0, 400, 300));

            panel1.DrawToBitmap(sourceBitmap, new System.Drawing.Rectangle(0, 0, 400, 300));

            sourceBitmap.Save(@"e:\123form2.bmp");

在图片上打水印

string strpath = @"e:\1.bmp";

            Bitmap bmp = new Bitmap(strpath);

            Graphics graphics = Graphics.FromImage(bmp);

            System.Drawing.SolidBrush myBrush = new System.Drawing.SolidBrush(System.Drawing.Color.Red);

            graphics.FillEllipse(myBrush, new System.Drawing.Rectangle(150, 200, 10, 10));//画圆

            try

            {

                bmp.Save(@"e:\new.bmp");

            }

            catch (Exception ex)

            {

                MessageBox.Show(ex.Message);

            }

抓屏截图
            Image objImage = new Bitmap(400, 300);

            Graphics g = Graphics.FromImage(objImage);

            g.CopyFromScreen(new System.Drawing.Point(Cursor.Position.X - 150, Cursor.Position.Y - 25), new System.Drawing.Point(0, 0), new Size(400, 300));

            IntPtr dc1 = g.GetHdc();

            g.ReleaseHdc(dc1);

            objImage.Save("e:\\test.jpg");

 

非顶端窗口截图

用Windows热键截图然后保存的我就不说了,地球人都知道.

如何截取非前端窗体的截图，要先获取所要截图的窗口的句柄IntPtr PicWindow = this.Handle

首先说一下PrintWindow这个API的使用

        public static Bitmap GetWindowCapture(IntPtr hWnd)

        {

            IntPtr hscrdc = GetWindowDC(hWnd);

            RECT windowRect = new RECT();

            GetWindowRect(hWnd, ref windowRect);

            int width = windowRect.right - windowRect.left;

            int height = windowRect.bottom - windowRect.top;

            IntPtr hbitmap = CreateCompatibleBitmap(hscrdc, width, height);

            IntPtr hmemdc = CreateCompatibleDC(hscrdc);

            SelectObject(hmemdc, hbitmap);

            PrintWindow(hWnd, hmemdc, 0);

            Bitmap bmp = Bitmap.FromHbitmap(hbitmap);

            DeleteDC(hscrdc);//删除用过的对象

            DeleteDC(hmemdc);//删除用过的对象

            return bmp;

        }

        [DllImport("user32.dll")]

        public static extern IntPtr GetWindowRect(IntPtr hWnd, ref RECT rect);

        [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 int BitBlt(

         IntPtr hdcDest, // handle to destination DC目标设备的句柄

         int nXDest,   // x-coord of destination upper-left corner目标对象的左上角的X坐标

         int nYDest,   // y-coord of destination upper-left corner目标对象的左上角的Y坐标

         int nWidth,   // width of destination rectangle目标对象的矩形宽度

         int nHeight, // height of destination rectangle目标对象的矩形长度

         IntPtr hdcSrc,   // handle to source DC源设备的句柄

         int nXSrc,    // x-coordinate of source upper-left corner源对象的左上角的X坐标

         int nYSrc,    // y-coordinate of source upper-left corner源对象的左上角的Y坐标

         UInt32 dwRop   // raster operation code光栅的操作值

         );

        [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("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

         );

很遗憾,上面的确可以截取非前端窗体的截图,但是非GDI的程序是无法截图的比如DirectX

 

下面说一下BitBlt这个API的使用

     /// <summary>

    /// 提供全屏和指定窗口的截图 以及保存为文件的类

    /// </summary>

    public class ScreenCapture

    {

        /// <summary>

        /// 全屏截图

        /// </summary>

        /// <returns></returns>

        public Image CaptureScreen()

        {

            return CaptureWindow(User32.GetDesktopWindow());

        }

        /// <summary>

        /// 指定窗口截图

        /// </summary>

        /// <param name="handle">窗口句柄. (在windows应用程序中, 从Handle属性获得)</param>

        /// <returns></returns>

        public Image CaptureWindow(IntPtr handle)

        {

            IntPtr hdcSrc = User32.GetWindowDC(handle);

            User32.RECT windowRect = new User32.RECT();

            User32.GetWindowRect(handle, ref windowRect);

            int width = windowRect.right - windowRect.left;

            int height = windowRect.bottom - windowRect.top;

            IntPtr hdcDest = GDI32.CreateCompatibleDC(hdcSrc);

            IntPtr hBitmap = GDI32.CreateCompatibleBitmap(hdcSrc, width, height);

            IntPtr hOld = GDI32.SelectObject(hdcDest, hBitmap);

            GDI32.BitBlt(hdcDest, 0, 0, width, height, hdcSrc, 0, 0, GDI32.SRCCOPY);

            GDI32.SelectObject(hdcDest, hOld);

            GDI32.DeleteDC(hdcDest);