This sample demonstrates how to create a simple PERT chart.
Each node represents an Activity and displays several pieces of information about each one. The node DataTemplate is basically a Grid holding TextBlocks that are data-bound to properties of the Activity. The Activity.Critical property controls whether the node is drawn with a red brush or a blue one.
There is a special converter that is used to control the brush used by the links. In a GraphModel there is no separate link data structure in the model for each Link. The data-binding gets a reference to a PartManager.VirtualLinkData, which takes the place of an application data structure for links. The converter is passed this "virtual" link data structure, from which it can examine the Activity data structures at both ends of the link in order to determine what color brush it should use.