This sample demonstrates one manner in which a diagram can focus on a selected node and all of the links and nodes connected to it, by only showing those nodes and links that are logically "near" to it. When the selection changes, the set of nodes and links that are shown in the diagram changes to focus on the newly selected node.

There is also another Diagram (the top one) that shows all of the nodes and links that are defined by a model. Selecting a node in either diagram will cause the bottom Diagram to focus on the newly selected node. To make it easier to see which node is selected when the diagram is zoomed far out, we have added a bright yellow highlight behind the selected node in the top Diagram.

Although it is not demonstrated in this sample, one could well use very simple DataTemplates for Nodes and for Links in the top Diagram. This would make the top Diagram more efficient to construct. And one could use more detailed DataTemplates in the bottom Diagram, where there is more room to show information for each node.