c# 根据窗口截图，合并图片

c# 根据窗口截图，合并图片

 public class CaptureWindows

    {

        #region 类

        /// <summary>

        /// Helper class containing User32 API functions

        /// </summary>

        private class User32

        {

            [StructLayout(LayoutKind.Sequential)]

            public struct RECT

            {

                public int left;

                public int top;

                public int right;

                public int bottom;

            }

            [DllImport("user32.dll")]

            public static extern IntPtr GetDesktopWindow();

            [DllImport("user32.dll")]

            public static extern IntPtr GetWindowDC(IntPtr hWnd);

            [DllImport("user32.dll")]

            public static extern IntPtr ReleaseDC(IntPtr hWnd, IntPtr hDC);

            [DllImport("user32.dll")]

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

        }

        private class GDI32

        {

            public const int SRCCOPY = 0x00CC0020; // BitBlt dwRop parameter

            [DllImport("gdi32.dll")]

            public static extern bool BitBlt(IntPtr hObject, int nXDest, int nYDest,

                int nWidth, int nHeight, IntPtr hObjectSource,

                int nXSrc, int nYSrc, int dwRop);

            [DllImport("gdi32.dll")]

            public static extern IntPtr CreateCompatibleBitmap(IntPtr hDC, int nWidth,

                int nHeight);

            [DllImport("gdi32.dll")]

            public static extern IntPtr CreateCompatibleDC(IntPtr hDC);

            [DllImport("gdi32.dll")]

            public static extern bool DeleteDC(IntPtr hDC);

            [DllImport("gdi32.dll")]

            public static extern bool DeleteObject(IntPtr hObject);

            [DllImport("gdi32.dll")]

            public static extern IntPtr SelectObject(IntPtr hDC, IntPtr hObject);

        }

        #endregion

        [DllImport("user32.dll", EntryPoint = "FindWindow")]

        public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);

        /// <summary>

        /// 根据句柄名截图

        /// </summary>

        /// <param name="handle">句柄名</param>

        /// <returns></returns>

        public Image CaptureWindow(IntPtr handle)

        {

            // get te hDC of the target window

            IntPtr hdcSrc = User32.GetWindowDC(handle);

            // get the size

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

            User32.GetWindowRect(handle, ref windowRect);

            int width = windowRect.right - windowRect.left;

            int height = windowRect.bottom - windowRect.top;

            // create a device context we can copy to

            IntPtr hdcDest = GDI32.CreateCompatibleDC(hdcSrc);

            // create a bitmap we can copy it to,

            // using GetDeviceCaps to get the width/height

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

            // select the bitmap object

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

            // bitblt over

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

            // restore selection

            GDI32.SelectObject(hdcDest, hOld);

            // clean up

            GDI32.DeleteDC(hdcDest);

            User32.ReleaseDC(handle, hdcSrc);

            // get a .NET image object for it

            Image img = Image.FromHbitmap(hBitmap);

            // free up the Bitmap object

            GDI32.DeleteObject(hBitmap);

            return img;

        }

        /// <summary>

        /// 根据窗口名称截图

        /// </summary>

        /// <param name="windowName">窗口名称</param>

        /// <returns></returns>

        public Image CaptureWindow(string windowName)

        {

            IntPtr handle = FindWindow(null, windowName);

            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);

            User32.ReleaseDC(handle, hdcSrc);

            Image img = Image.FromHbitmap(hBitmap);

            GDI32.DeleteObject(hBitmap);

            return img;

        }

        /// <summary>

        /// 合并图片

        /// </summary>

        /// <param name="firstImage">第一张图片</param>

        /// <param name="lastImage">第二张图片</param>

        /// <returns></returns>

        public Image MergerImage(Image firstImage, Image lastImage)

        {

            int width = firstImage.Width + lastImage.Width ;

            int height = firstImage.Height > lastImage.Height ? firstImage.Height : lastImage.Height;

            ////创建要显示的图片对象,根据参数的个数设置宽度

            Bitmap backgroudImg = new Bitmap(width, height);

            Graphics g = Graphics.FromImage(backgroudImg);

            ////清除画布,背景设置为白色

            g.Clear(System.Drawing.Color.White);

            g.DrawImageUnscaled(firstImage, 0, 0);

            g.DrawImageUnscaled(lastImage, firstImage.Width, 0);

            g.Dispose();

            return backgroudImg;

        }

    }