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  • Question

  • i want to get active window screenshot. i do not want to get all the screen. i want to run code in form and capture form. can i do it without bitmap
    Saturday, June 30, 2018 4:03 PM

Answers

  • Hi Tinnaa,

    Thank you for posting here.

    For your question, please try the code below.

     public partial class Form1 : Form
        {
            public Form1()
            {
                InitializeComponent();
            }
    
            private void button1_Click(object sender, EventArgs e)
            {
    
                ScreenCapture sc = new ScreenCapture();
                // capture entire screen, and save it to a file
                Image img = sc.CaptureScreen();
                // display image in a Picture control named imageDisplay
                //this.pictureBox1.Image = img;
    
                // capture this window, and save it
                sc.CaptureWindowToFile(this.Handle, "temp2.gif", ImageFormat.Gif);
               
                MessageBox.Show("Screen Captured");        
            }   
        }
        /// <summary>
        /// Provides functions to capture the entire screen, or a particular window, and save it to a file.
        /// </summary>
        public class ScreenCapture
        {
            /// <summary>
            /// Creates an Image object containing a screen shot of the entire desktop
            /// </summary>
            /// <returns></returns>
            public Image CaptureScreen()
            {
                return CaptureWindow(User32.GetDesktopWindow());
            }
            /// <summary>
            /// Creates an Image object containing a screen shot of a specific window
            /// </summary>
            /// <param name="handle">The handle to the window. (In windows forms, this is obtained by the Handle property)</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>
            /// Captures a screen shot of a specific window, and saves it to a file
            /// </summary>
            /// <param name="handle"></param>
            /// <param name="filename"></param>
            /// <param name="format"></param>
            public void CaptureWindowToFile(IntPtr handle, string filename, ImageFormat format)
            {
                Image img = CaptureWindow(handle);
                img.Save(filename, format);
            }
            /// <summary>
            /// Captures a screen shot of the entire desktop, and saves it to a file
            /// </summary>
            /// <param name="filename"></param>
            /// <param name="format"></param>
            public void CaptureScreenToFile(string filename, ImageFormat format)
            {
                Image img = CaptureScreen();
                img.Save(filename, format);
            }
    
            /// <summary>
            /// Helper class containing Gdi32 API functions
            /// </summary>
            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);
            }
    
            /// <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);
            }
        }

    Best Regards,

    Wendy


    MSDN Community Support
    Please remember to click "Mark as Answer" the responses that resolved your issue, and to click "Unmark as Answer" if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to MSDN Support, feel free to contact MSDNFSF@microsoft.com.

    • Marked as answer by Tinnaa Monday, July 2, 2018 1:29 AM
    Saturday, June 30, 2018 4:21 PM

All replies

  • Hi Tinnaa,

    Thank you for posting here.

    For your question, please try the code below.

     public partial class Form1 : Form
        {
            public Form1()
            {
                InitializeComponent();
            }
    
            private void button1_Click(object sender, EventArgs e)
            {
    
                ScreenCapture sc = new ScreenCapture();
                // capture entire screen, and save it to a file
                Image img = sc.CaptureScreen();
                // display image in a Picture control named imageDisplay
                //this.pictureBox1.Image = img;
    
                // capture this window, and save it
                sc.CaptureWindowToFile(this.Handle, "temp2.gif", ImageFormat.Gif);
               
                MessageBox.Show("Screen Captured");        
            }   
        }
        /// <summary>
        /// Provides functions to capture the entire screen, or a particular window, and save it to a file.
        /// </summary>
        public class ScreenCapture
        {
            /// <summary>
            /// Creates an Image object containing a screen shot of the entire desktop
            /// </summary>
            /// <returns></returns>
            public Image CaptureScreen()
            {
                return CaptureWindow(User32.GetDesktopWindow());
            }
            /// <summary>
            /// Creates an Image object containing a screen shot of a specific window
            /// </summary>
            /// <param name="handle">The handle to the window. (In windows forms, this is obtained by the Handle property)</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>
            /// Captures a screen shot of a specific window, and saves it to a file
            /// </summary>
            /// <param name="handle"></param>
            /// <param name="filename"></param>
            /// <param name="format"></param>
            public void CaptureWindowToFile(IntPtr handle, string filename, ImageFormat format)
            {
                Image img = CaptureWindow(handle);
                img.Save(filename, format);
            }
            /// <summary>
            /// Captures a screen shot of the entire desktop, and saves it to a file
            /// </summary>
            /// <param name="filename"></param>
            /// <param name="format"></param>
            public void CaptureScreenToFile(string filename, ImageFormat format)
            {
                Image img = CaptureScreen();
                img.Save(filename, format);
            }
    
            /// <summary>
            /// Helper class containing Gdi32 API functions
            /// </summary>
            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);
            }
    
            /// <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);
            }
        }

    Best Regards,

    Wendy


    MSDN Community Support
    Please remember to click "Mark as Answer" the responses that resolved your issue, and to click "Unmark as Answer" if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to MSDN Support, feel free to contact MSDNFSF@microsoft.com.

    • Marked as answer by Tinnaa Monday, July 2, 2018 1:29 AM
    Saturday, June 30, 2018 4:21 PM
  • A simple way :

    using (var bmp = new Bitmap(this.Width, this.Height))
    {
        this.DrawToBitmap(bmp, new Rectangle(0, 0, bmp.Width, bmp.Height));
        bmp.Save(@"E:\Form_screenshot.jpg", System.Drawing.Imaging.ImageFormat.Jpeg);
    }

    Saturday, June 30, 2018 4:34 PM