调用摄像头为什么只有全黑

Question

capCreateCaptureWindowA调用后panel里只有全黑没有任何图片,已经测试过射像头是好的应该怎么改?

Answer 1

把panel调大点试试，看看有没有弹出选项框

Answer 2

Private hWndC As IntPtr
'
hWndC = capCreateCaptureWindowA(lpszName, WS_CHILD Or WS_VISIBLE, mLeft, mTop, mWidth, mHeight, Picture1.Handle, 0)
            If hWndC.ToInt32() <> 0 Then
                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)
            End IfSIGNATURE:----------------------------------------------------------------

Answer 3

  /// <summary>
        /// 打开摄像头
        /// </summary>
        public void StartWebCam()
        {
            byte[] lpszName = new byte[100];
            byte[] lpszVer = new byte[100];
            VideoAPI.capGetDriverDescriptionA(0, lpszName, 100, lpszVer, 100);
            lwndC = VideoAPI.capCreateCaptureWindowA(lpszName, VideoAPI.WS_CHILD | VideoAPI.WS_VISIBLE, 0, 0, mWidth, mHeight, mControlPtr, 0);
            if (VideoAPI.SendMessage(lwndC, VideoAPI.WM_CAP_DRIVER_CONNECT, 0, 0))//驱动程序连接
            {
                VideoAPI.SendMessage(lwndC, VideoAPI.WM_CAP_SET_PREVIEWRATE, 100, 0);//设置预览比例 52
                VideoAPI.SendMessage(lwndC, VideoAPI.WM_CAP_SET_PREVIEW, true, 0);//设置预览 50
            }
        }

Answer 4

我就是这么写的但是panel里永远只有黑色!射像头用windows自带的那个工具测试过有图象