Problems with DiagramBitmapRenderer

I'm trying to use the bitmap renderer but nothing seems to work. Saving to file (png, bmp, jpeg) saves only a black square. Saving to stream has different effects: in png, I get the same black square. With bmp I get an ArgumentOutOfRangeException ({"The parameter value must be greater than zero.\r\nParameter name: pixelWidth"}). With jpeg I get a wrong header (as reported by BitmapFrame). The code is extremely simple (the same in all cases, except for the diagram renderer implementation):

  var stream = new System.IO.MemoryStream();
  DiagramBitmapRenderer.Jpeg.Render(element, stream);
  var frame = BitmapFrame.Create(stream, BitmapCreateOptions.None, BitmapCacheOption.None);
  Clipboard.SetImage(frame);

Any help would be highly appreciated.

J

Hello Joaquin

I will look into this for you on the first day back from our break.

-Jason Fauchelle

Hello Joaquin

The exceptions can be resolved by resetting the position of the stream back to 0 before using the BitmapFrame. Here is an update of your code example that does this:

var stream = new System.IO.MemoryStream();
DiagramBitmapRenderer.Jpeg.Render(ds, stream);
stream.Seek(0, System.IO.SeekOrigin.Begin);
var frame = BitmapFrame.Create(stream, BitmapCreateOptions.None, BitmapCacheOption.None);
Clipboard.SetImage(frame);

The black background is caused by the compatibility of transparency. I've improved the bitmap renderer to use the background of the diagram in the image. Please install the next nightly build, and then set the Background property of your DiagramSurface to White (or whatever you want), and then try exporting the images.

Let me know how it goes.

-Jason Fauchelle