网络摄像头预览中的图像引发通用GDI +异常

Question

I'm making a custom webcam user control.

I use Microsoft Expression Encoder, and set a PreviewWindow on a panel inside the control.

All's fine, except that when I try to grab the image, I get an exception:

Generic GDI+ exception

My first try was:

using (var bmp = new Bitmap(p.Width, p.Width))
            {
                panel1.DrawToBitmap(bmp, new Rectangle(0, 0, bmp.Width, bmp.Height));
                bmp.Save(@"c:\test.png");
            }

Another waS:

using (Bitmap bitmap = new Bitmap(panelVideoPreview.Width, panelVideoPreview.Height))
          { 
              using (Graphics g = Graphics.FromImage(bitmap))
              {
                  Rectangle rectanglePanelVideoPreview = panelVideoPreview.Bounds;

             Point sourcePoints = panelVideoPreview.PointToScreen(new Point(panelVideoPreview.ClientRectangle.X, panelVideoPreview.ClientRectangle.Y));
             g.CopyFromScreen(sourcePoints, Point.Empty, rectanglePanelVideoPreview.Size); 
              }

              string strGrabFileName = String.Format("C:\\Snapshot.jpg", DateTime.Now);
              bitmap.Save(strGrabFileName, ImageFormat.Jpeg);        

Answer 1

The problem is in writing the file. There may not be enough space in c:\\ drive or you do not have permission to write to c:\\ drive(outside a folder). Try writing to AppData ,if you want to write to c:\\ drive,you need to acquire administrative privileges by using a custom manifest.