I can address your "topology graph edit operation caused a feature geometry to become empty" error problem. Before you move the topology edge corresponding to the polygon's edge, you have to make sure that the corresponding topology edge is selected. topoGraph.SelectByGeometry((int)esriTopologyElementType.esriTopologyEdge, esriTopologySelectionResultEnum.esriTopologySelectionResultNew, pointOnPolygonEdge); Then you'll be able to call SetEdgeGeometry without emptying the topology, and post without generating the error. If you're moving any topology nodes, you have to make sure that no topology edges are selected on the graph and that only that topology node is selected. _topoGraph.SetSelectionEmpty((int)esriTopologyElementType.esriTopologyEdge); _topoGraph.SelectByGeometry((int)esriTopologyElementType.esriTopologyNode, esriTopologySelectionResultEnum.esriTopologySelectionResultNew, nodePoint); If you dont make these selections/deselections before moving, it will cause the topology graph to become empty, and when you post, it will generate that error.
... View more