namespace  webcam

{

     using  System;

     using  System.Runtime.InteropServices;

     using  System.Windows.Forms;

     ///   <summary>

     ///  Leon's webcam mirror

     ///   </summary>

     public   partial   class  WebCam : Form

    {

         ///   <summary>

         ///  Webcam handle. 

         ///   </summary>

         private   int  hHwnd;

         public  WebCam()

        {

            InitializeComponent();

        }

         public   struct  videohdr_tag

        {

             public   byte [] lpData;

             public   int  dwBufferLength;

             public   int  dwBytesUsed;

             public   int  dwTimeCaptured;

             public   int  dwUser;

             public   int  dwFlags;

             public   int [] dwReserved;

        }

         #region  P/Invoke

        [DllImport( " avicap32.dll " , CharSet  =  CharSet.Ansi, SetLastError  =   true , ExactSpelling  =   true )]

         public   static   extern   int  capCreateCaptureWindowA([MarshalAs(UnmanagedType.VBByRefStr)]    ref     string  lpszWindowName,  int  dwStyle,  int  x,  int  y,  int  nWidth,  short  nHeight,  int  hWndParent,  int  nID);

        [DllImport( " avicap32.dll " , CharSet  =  CharSet.Ansi, SetLastError  =   true , ExactSpelling  =   true )]

         public   static   extern   bool  capGetDriverDescriptionA( short  wDriver, [MarshalAs(UnmanagedType.VBByRefStr)]    ref     string  lpszName,  int  cbName, [MarshalAs(UnmanagedType.VBByRefStr)]    ref     string  lpszVer,  int  cbVer);

        [DllImport( " user32 " , CharSet  =  CharSet.Ansi, SetLastError  =   true , ExactSpelling  =   true )]

         public   static   extern   bool  DestroyWindow( int  hndw);

        [DllImport( " user32 " , EntryPoint  =   " SendMessageA " , CharSet  =  CharSet.Ansi, SetLastError  =   true , ExactSpelling  =   true )]

         public   static   extern   int  SendMessage( int  hwnd,  int  wMsg,  int  wParam, [MarshalAs(UnmanagedType.AsAny)]    object  lParam);

        [DllImport( " user32 " , CharSet  =  CharSet.Ansi, SetLastError  =   true , ExactSpelling  =   true )]

         public   static   extern   int  SetWindowPos( int  hwnd,  int  hWndInsertAfter,  int  x,  int  y,  int  cx,  int  cy,  int  wFlags);

        [DllImport( " vfw32.dll " )]

         public   static   extern   string  capVideoStreamCallback( int  hwnd, videohdr_tag videohdr_tag);

        [DllImport( " vicap32.dll " , CharSet  =  CharSet.Ansi, SetLastError  =   true , ExactSpelling  =   true )]

         public   static   extern   bool  capSetCallbackOnFrame( int  hwnd,  string  s);

         #endregion

         ///   <summary>

         ///  Initialize webcam and display the video in a panel.

         ///   </summary>

         ///   <returns></returns>

         private   bool  InitializeWebcam()

        {

             bool  ok  =   false ;

             int  intWidth  =   this .panel1.Width;

             int  intHeight  =   this .panel1.Height;

             int  intDevice  =   0 ;

             string  refDevice  =  intDevice.ToString();

             // Create vedio and get the window handle.

            hHwnd  =  WebCam.capCreateCaptureWindowA( ref  refDevice,  1342177280 ,  0 ,  0 ,  640 ,  480 ,  this .panel1.Handle.ToInt32(),  0 );

           

             if  (WebCam.SendMessage(hHwnd,  0x40a , intDevice,  0 )  >   0 )

            {

                WebCam.SendMessage( this .hHwnd,  0x435 ,  - 1 ,  0 );

                WebCam.SendMessage( this .hHwnd,  0x434 ,  0x42 ,  0 );

                WebCam.SendMessage( this .hHwnd,  0x432 ,  - 1 ,  0 );

                WebCam.SetWindowPos( this .hHwnd,  1 ,  0 ,  0 , intWidth, intHeight,  6 );

                ok  =   true ;

            }

             else

            {

                WebCam.DestroyWindow( this .hHwnd);

            }

             return  ok;

        }

         ///   <summary>

         ///  App run, then invoke the webcam till successfully.

         ///   </summary>

         ///   <param name="sender"></param>

         ///   <param name="e"></param>

         private   void  WebCam_Load( object  sender, EventArgs e)

        {

             bool  ok  =   false ;

             while  ( ! ok)

            {

                ok  =   this .InitializeWebcam();

                System.Threading.Thread.Sleep( 100 );

            }

        }

         private   void  CloseWebcam()

        {

             if  ( this .hHwnd  >   0 )

            {

                WebCam.SendMessage( this .hHwnd,  0x40b ,  0 ,  0 );

                WebCam.DestroyWindow( this .hHwnd);

            }

        }

         ///   <summary>

         ///  when close window, destroy the webcam window.

         ///   </summary>

         ///   <param name="sender"></param>

         ///   <param name="e"></param>

         private   void  WebCam_FormClosed( object  sender, FormClosedEventArgs e)

        {

            CloseWebcam();

        }

         ///   <summary>

         ///  when window size changed, resize webcam pic.

         ///   </summary>

         ///   <param name="sender"></param>

         ///   <param name="e"></param>

         private   void  WebCam_SizeChanged( object  sender, EventArgs e)

        {

            WebCam.SetWindowPos( this .hHwnd,  1 ,  0 ,  0 , this .Width, this .Height,  6 );

        }

    }

}