You can try several techniques to avoid this problem:
- Invoke the Layout operation in the GraphSourceChanged event handler of the RadDiagram. Please also set Width and Height to the RadDiagramShapes via Style. The GraphSource changed event fires after the shapes have been measured.
- Invoke the Layout operation in the Loaded event handler in a Dispatcher body
- Invoke the Layout operation in the SizeChanged event handler in a Dispatcher body
The usual reason for this issue is that the Layout is invoked too early and the shapes are not measured yet. We hope the first, or some of the other approaches proposed will fit in your scenario.
the Telerik team