Question

我在捕捉和处理异常方面遇到了一些麻烦。我的（简化）应用程序有一个图片框，显示来自连接的网络摄像头的实时视频。我使用Metrilius Metricam SDK（http://www.metrilus.de/blog/portfolio-items/metricam/）连接到网络摄像头。使用backgroundworker，我调用camera.update函数，抓取位图并将图片框设置为它。只要用户点击Enter，就会抓取并存储当前帧。如前所述，当使用来自摄像头的最新bmp更新图片框时，会在完全随机的时间点抛出异常。正如您在下面的代码中看到的，我已将赋值包装在try / catch块中，但它并没有捕获它。我能做些什么来优雅地处理这件事？异常在图片框上绘制一个大的红色X，程序必须关闭并重新启动。 picturebox的sizemode属性设置为Zoom。

以下代码：

Private Sub BG1_DoWork(sender As Object, e As DoWorkEventArgs) Handles BG1.DoWork
    While Not BG1.CancellationPending

        If pauseCamUpdate = False Then 'PausecamUpdate is a flag that is set to False during calls to store the current frame
            i += 1
            If i Mod 2 = 0 Then Continue While 'Dropping every nth frame to make the update smoother
            If i > 10000 Then
                i = 0
            End If
            Try
                activeCam.Update()
                pictPhoto.Image = CType(CType(activeCam, WebCam).CalcBitmap(), Bitmap)
                'pictPhoto.Invalidate()
                 Application.DoEvents()
            Catch exp As Exception 
            End Try
        End If
    End While
End Sub

异常文本减去加载的程序集：

See the end of this message for details on invoking
just-in-time (JIT) debugging instead of this dialog box.

************** Exception Text **************

**System.InvalidOperationException: Object is currently in use elsewhere.**
at System.Drawing.Image.get_Height()
at System.Drawing.Image.get_Size()
at 

System.Windows.Forms.PictureBox.ImageRectangleFromSizeMode(PictureBoxSizeMode mode)
at System.Windows.Forms.PictureBox.OnPaint(PaintEventArgs pe)
at System.Windows.Forms.Control.PaintWithErrorHandling(PaintEventArgs e, 
Int16 layer)
at System.Windows.Forms.Control.WmPaint(Message& m)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr 
wparam, IntPtr lparam)

感谢您的帮助。

捕获框架异常

0 个答案: