If you want to pan a RadDiagram
without holding a key, you can set the ActiveTool property to PanTool. But please note that this way you won't be able to select or manipulate RadDiagram's
items. That's why if you don't want to lose the diagram's interactivity, you could handle the KeyDown and KeyUp events and in their handler if certain key is pressed to change the ActiveTool dynamically. You can check the implementation of this approach here
Unfortunately you can't use one of the mouse buttons to pan and the other to select items, because even if you handle the RightMouseButtonDown event you should hold both mouse buttons to pan.
If you have more questions don't hesitate to contact us.