我想在我的.net程序中调用摄象头大体应该怎么做

wuxiao_v 2008-04-06 01:12:46

只需要给一个大体的方向就可以,我对.net很陌生但是有其他编程经验

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tellyes 2008-04-09

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[DllImport("avicap32.dll", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)] //引用非托管动态链接库
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); //这句里面比较难理解的是[MarshalAs(UnmanagedType.VBByRefStr)] ref string lpszWindowName，意思是将托管的string类型看作是非托管的VBByRefStr

wuxiao_v 2008-04-09

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[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);

谁能帮我解释一下这段代码大体什么意思

hopewoo 2008-04-06

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我好像给太多了...

hopewoo 2008-04-06

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  public partial class Form1 : Form

    {





        #region API

        [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





        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;



        }



        IntPtr vhandle;

        private const int WM_CAP_EDIT_COPY = 0x41E;

        private const int WM_CAP_SET_SCALE = 0x435;

        private const int WM_CAP_SET_PREVIEWRATE = 0x434;

        private const int WM_CAP_SET_PREVIEW = 0x432;

        private void OpenCapture()

        {



            int intWidth = 160;

            int intHeight = 120;

            int intDevice = 0;

            string refDevice = intDevice.ToString();

            hHwnd = capCreateCaptureWindowA(ref   refDevice, 1342177280, 0, 0, 160, 120, vhandle.ToInt32(), 0);

            //this.LbSysMsg.Text = "";

            //this.LbSysMsg.Text += "驱动:" + refDevice;

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

            {

                SendMessage(this.hHwnd, WM_CAP_SET_SCALE, -1, 0);

                SendMessage(this.hHwnd, WM_CAP_SET_PREVIEWRATE, 0x42, 0);

                SendMessage(this.hHwnd, WM_CAP_SET_PREVIEW, -1, 0);

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

            }

            else

            {

                DestroyWindow(this.hHwnd);

            }

        }





        private int hHwnd;

        public Form1()

        {



            this.SetStyle(ControlStyles.SupportsTransparentBackColor, true);

            InitializeComponent();

          

        }



        private void Form1_Load(object sender, EventArgs e)

        {

            vhandle = this.Handle;

            OpenCapture();

        }





        



      

    }