Example of c implementing camera photo taking function

  • 2020-06-19 11:38:21
  • OfStack


using System.Drawing;
using System.Drawing.Imaging;
using System;
using System.Runtime.InteropServices;


private const int WM_USER = 0x400;
private const int WS_CHILD = 0x40000000;
private const int WS_VISIBLE = 0x10000000;
private const int WM_CAP_START = WM_USER;
private const int WM_CAP_STOP = WM_CAP_START + 68;
private const int WM_CAP_DRIVER_CONNECT = WM_CAP_START + 10;
private const int WM_CAP_DRIVER_DISCONNECT = WM_CAP_START + 11;
private const int WM_CAP_SAVEDIB = WM_CAP_START + 25;
private const int WM_CAP_GRAB_FRAME = WM_CAP_START + 60;
private const int WM_CAP_SEQUENCE = WM_CAP_START + 62;
private const int WM_CAP_FILE_SET_CAPTURE_FILEA = WM_CAP_START + 20;
private const int WM_CAP_SEQUENCE_NOFILE = WM_CAP_START + 63;
private const int WM_CAP_SET_OVERLAY = WM_CAP_START + 51;
private const int WM_CAP_SET_PREVIEW = WM_CAP_START + 50;
private const int WM_CAP_SET_CALLBACK_VIDEOSTREAM = WM_CAP_START + 6;
private const int WM_CAP_SET_CALLBACK_ERROR = WM_CAP_START + 2;
private const int WM_CAP_SET_CALLBACK_STATUSA = WM_CAP_START + 3;
private const int WM_CAP_SET_CALLBACK_FRAME = WM_CAP_START + 5;
private const int WM_CAP_SET_SCALE = WM_CAP_START + 53;
private const int WM_CAP_SET_PREVIEWRATE = WM_CAP_START + 52;
private IntPtr hWndC;
private bool bStat = false;
private IntPtr mControlPtr;
private int mWidth;
private int mHeight;
private int mLeft;
private int mTop;


/// <summary>
///  Initialization camera 
/// </summary>
/// <param name="handle"> Handle to the control </param>
/// <param name="left"> Start showing the left margin </param>
/// <param name="top"> The top margin to start displaying </param>
/// <param name="width"> The width to display </param>
/// <param name="height"> The length to display </param>
public VideoClass(IntPtr handle, int left, int top, int width, int height)
{
    mControlPtr = handle;
    mWidth = width;
    mHeight = height;
    mLeft = left;
    mTop = top;
}


[DllImport("avicap32.dll")]
private static extern IntPtr capCreateCaptureWindowA(byte[] lpszWindowName, int dwStyle, int x, int y, int nWidth, int nHeight, IntPtr hWndParent, int nID);
[DllImport("avicap32.dll")]
private static extern int capGetVideoFormat(IntPtr hWnd, IntPtr psVideoFormat, int wSize);
[DllImport("User32.dll")]
private static extern bool SendMessage(IntPtr hWnd, int wMsg, int wParam, long lParam);
[DllImport("avicap32.dll")]
public static extern bool capGetDriverDescriptionA(short wDriver, byte[] lpszName, int cbName, byte[] lpszVer, int cbVer);


/// <summary>
///  Start displaying images 
/// </summary>
public void Start()
{
    if (bStat)
return;
    bStat = true;
    byte[] lpszName = new byte[100];
    hWndC = capCreateCaptureWindowA(lpszName, WS_CHILD | WS_VISIBLE, mLeft, mTop, mWidth, mHeight, mControlPtr, 0);
    if (hWndC.ToInt32() != 0)
    {
SendMessage(hWndC, WM_CAP_SET_CALLBACK_VIDEOSTREAM, 0, 0);
SendMessage(hWndC, WM_CAP_SET_CALLBACK_ERROR, 0, 0);
SendMessage(hWndC, WM_CAP_SET_CALLBACK_STATUSA, 0, 0);
SendMessage(hWndC, WM_CAP_DRIVER_CONNECT, 0, 0);
SendMessage(hWndC, WM_CAP_SET_SCALE, 1, 0);
SendMessage(hWndC, WM_CAP_SET_PREVIEWRATE, 66, 0);
SendMessage(hWndC, WM_CAP_SET_OVERLAY, 1, 0);
SendMessage(hWndC, WM_CAP_SET_PREVIEW, 1, 0);
    }
    return;
}


/// <summary>
///  To stop showing 
/// </summary>
        public void Stop()
        {
            SendMessage(hWndC, WM_CAP_DRIVER_DISCONNECT, 0, 0);
            bStat = false;
        }
        /// <summary>
///  screenshots 
/// </summary>
/// <param name="path"> To save the bmp Path to file </param>
        public void GrabImage(string path)
        {
            IntPtr hBmp = Marshal.StringToHGlobalAnsi(path);
            SendMessage(hWndC, WM_CAP_SAVEDIB, 0, hBmp.ToInt64());
        }
        /// <summary>
///  video 
/// </summary>
/// <param name="path"> To save the avi Path to file </param>
        public void Kinescope(string path)
        {
            IntPtr hBmp = Marshal.StringToHGlobalAnsi(path);
            SendMessage(hWndC, WM_CAP_FILE_SET_CAPTURE_FILEA, 0, hBmp.ToInt64());
            SendMessage(hWndC, WM_CAP_SEQUENCE, 0, 0);
        }
        /// <summary>
///  Stop the video 
/// </summary>
        public void StopKinescope()
        {
            SendMessage(hWndC, WM_CAP_STOP, 0, 0);
        }


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