Assigning point position to node

[wbarisch]

Is there a way to specify the position of a node in the graph? For example: Graph graph = graphViewer.Graph; graph.AddNode("2"); Microsoft.Msagl.Core.Geometry.Point position = (199,991); graph.FindNode("2").GeometryNode.Center = position; graphViewer.Graph = graph;

This code doesn't change the position of the point. Up to the "graphViewer.Graph = graph;" graph still has the right node("2") position, but after the last command, both graph and graphViewer.Graph change node's position to the original. Any tips how to solve this? Thank you

[levnach]

The statement graphViewer.Graph = graph; actually does a lot of work: it calls the layout algorithm that sets the node positions and routes the edges, and then graph is rendered. Setting the center of the node before this statement will not have any effect.

It is not a popular scenario, but you can take over the layout and pre-calculate all the geometry, then set graphViewer.NeedToCalculateLayout = false; before calling graphViewer.Graph = graph;. In this case your geometry will be preserved.

[wbarisch]

Thank you for answering. It does work with graphViewer.NeedToCalculateLayout = false;. Does the statement graph.AddEdge("node1", "node2"); also calls for the layout algorithm? Assuming both nodes are already in the graph, but their original positions have been changed. I've tried to set an edge after changing the nodes position and got an NullReferenceException.

[levnach]

No, it does not.