Using a Webcam without DirectShow.

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C#

Hi, I wanted to know if there is a way of getting my integrated webcam to work without using an external DLL such as directshow etc... I have found some code online, but some the device id is not getting set or it requires external references. The following uses a System 32 API call but device ID remains blank, not to sure how to set it!

class WebCamera : IDisposable
    {
        #region Constants
        /// <summary>
        /// Constants are used to overload unmanaged code functions
        /// Each Constant represents a state
        /// </summary>
        private const short WM_CAP = 0x400;
        private const int WM_CAP_DRIVER_CONNECT = 0x40a;
        private const int WM_CAP_DRIVER_DISCONNECT = 0x40b;
        private const int WM_CAP_EDIT_COPY = 0x41e;
        private const int WM_CAP_SET_PREVIEW = 0x432;
        private const int WM_CAP_SET_OVERLAY = 0x433;
        private const int WM_CAP_SET_PREVIEWRATE = 0x434;
        private const int WM_CAP_SET_SCALE = 0x435;
        private const int WS_CHILD = 0x40000000;
        private const int WS_VISIBLE = 0x10000000;
        private const short SWP_NOMOVE = 0x2;
        private short SWP_NOZORDER = 0x4;
        private short HWND_BOTTOM = 1;
        #endregion

        #region DLLs and properties
        /// <summary>
        /// DllImport allows you to import dlls on the system for your code to cominicate with
        /// This function enables enumerate of WebCam devices
        /// </summary>
        [DllImport("avicap32.dll")]
        protected static extern bool capGetDriverDescriptionA(short wDriverIndex,
                                                              [MarshalAs(UnmanagedType.VBByRefStr)] ref String IpszName,
                                                              int cbName, [MarshalAs(UnmanagedType.VBByRefStr)] ref String IpszVer, int cbVer);
        /// <summary>
        /// DllImport allows you to import dlls on the system for your code to cominicate with
        /// Creates a window child, so that you can display it in a PictureBox
        /// </summary>
        [DllImport("avicap32.dll")]
        protected static extern int capCreateCaptureWindowA([MarshalAs(UnmanagedType.VBByRefStr)] ref string lpszWindowName,
                                                            int dwStyle, int x, int y, int nWidth, int nHeight, int hWndParent, int nID);

        /// <summary>
        /// DllImport allows you to import dlls on the system for your code to cominicate with
        /// This function enables set changes to the size, position, and Z order of a child window
        /// </summary>
        /// <param name="hwnd"></param>
        /// <param name="hWndInsertAfter"></param>
        /// <param name="x"></param>
        /// <param name="y"></param>
        /// <param name="cx"></param>
        /// <param name="cy"></param>
        /// <param name="wFlags"></param>
        /// <returns></returns>
        [DllImport("user32")]
        protected static extern int SetWindowPos(int hwnd, int hWndInsertAfter, int x, int y, int cx, int cy, int wFlags);

        /// <summary>
        /// DllImport allows you to import dlls on the system for your code to cominicate with
        /// This function enables send the specified message to a window or windows
        /// </summary>
        /// <param name="hwnd"></param>
        /// <param name="wMsg"></param>
        /// <param name="wParam"></param>
        /// <param name="lParam"></param>
        /// <returns></returns>
        [DllImport("user32", EntryPoint = "SendMessageA")]
        protected static extern int SendMessage(int hwnd, int wMsg, int wParam, [MarshalAs(UnmanagedType.AsAny)] object lParam);

        /// <summary>
        /// DllImport allows you to import dlls on the system for your code to cominicate with
        /// This function enable destroy the window child
        /// </summary>
        /// <param name="hwnd"></param>
        /// <returns></returns>
        [DllImport("user32")]
        protected static extern bool DestroyWindow(int hwnd);

        // Normal device ID
        int DeviceID = 0;
        // Handle Value to preview window
        int hHwnd = 0;
        // The list of devices
        ArrayList ListOfDevices = new ArrayList();
        //Display stream in PictureBox
        public PictureBox Container { get; set; }
        #endregion

        #region Load Method
        // Connects to device.
        /// <summary>
        /// This function is used to load the list of devices
        /// </summary>
        public void Load()
        {
            string Name = String.Empty.PadRight(100);
            string Version = String.Empty.PadRight(100);
            bool EndOfDeviceList = false;
            short index = 0;

            //Load and name all of available devices into ListOfDevices
            do
            {
                //Get Driver Name and Version
                EndOfDeviceList = capGetDriverDescriptionA(index, ref Name, 100, ref Version, 100);
                //
                if (EndOfDeviceList) ListOfDevices.Add(Name.Trim());
                index += 1;
            }
            while (!(EndOfDeviceList == false));
        }
        #endregion

        #region Open Connection
        public void OpenConnection()
        {
            Load();

            string DeviceIndex = Convert.ToString(DeviceID);
            // Setting the Container(PictureBox) to handle the Device
            IntPtr oHandle = Container.Handle;
            {
                MessageBox.Show("Set the container property");
            }

            // Open Preview window in picturebox .
            // Create a child window with capCreateCaptureWindowA so you can display it in a picturebox.
            hHwnd = capCreateCaptureWindowA(ref DeviceIndex, WS_VISIBLE | WS_CHILD, 0, 0, 640, 480, oHandle.ToInt32(), 0);

            // Connect to the device
            if (SendMessage(hHwnd, WM_CAP_DRIVER_CONNECT, DeviceID, 0) != 0)
            {
                // Set the preview scale
                SendMessage(hHwnd, WM_CAP_SET_SCALE, -1, 0);
                // Set the preview rate in terms of milliseconds
                SendMessage(hHwnd, WM_CAP_SET_PREVIEWRATE, 66, 0);
                // Start previewing the image from the camera
                SendMessage(hHwnd, WM_CAP_SET_PREVIEW, -1, 0);
                //Resize window to fit the PictureBox
                SetWindowPos(hHwnd, HWND_BOTTOM, 0, 0, Container.Height, Container.Width, SWP_NOMOVE | SWP_NOZORDER);
            }
            else
            {
                // Close device due to connection error
                DestroyWindow(hHwnd);
            }
        }
        #endregion

        #region Close Connection
        public void CloseConnection()
        {
            SendMessage(hHwnd, WM_CAP_DRIVER_DISCONNECT, DeviceID, 0);
            // Close Window
            DestroyWindow(hHwnd);
        }
        #endregion

        #region Save Image
        /// <summary>
        /// Allows you to save image to local machine as type Bmp
        /// </summary>
        public void SaveImage()
        {
            IDataObject data;
            Image oImage;
            SaveFileDialog saveImage = new SaveFileDialog();
            saveImage.Filter = "(*.bmp)|*.bmp";
            // Copy Image to clipboard
            SendMessage(hHwnd, WM_CAP_EDIT_COPY, 0, 0);

            // Get Image from clipboard and convert it to a bitmap
            data = Clipboard.GetDataObject();
            if (data.GetDataPresent(typeof(System.Drawing.Bitmap)))
            {
                oImage = (Image)data.GetData(typeof(System.Drawing.Bitmap));
                Container.Image = oImage;
                CloseConnection();
                if (saveImage.ShowDialog() == DialogResult.OK)
                {
                    oImage.Save(saveImage.FileName, System.Drawing.Imaging.ImageFormat.Bmp);
                }
            }
        }
        #endregion

        #region Dispose Method
        /// <summary>
        /// Closes the connection to device and dumps all remaining memory usage
        /// </summary>
        public void Dispose()
        {
            CloseConnection();
        }
        #endregion
    }