In order to display just those three properties, the sample defines a NodeProps class and assigns its instance to PropertyGrid.SelectedObject, instead of the actual selected ShapeNode. So you must update the NodeProps.Text property too, or simply assign ShapeNodes to the PropertyGrid, instead of going through the intermediary object.

I hope that helps,
Stoyan

Dim node As ShapeNode = CType(_doc.ActiveItem, ShapeNode)
node.Text = "XXX"
_selected.Text = node.Text
_propertyGrid.Refresh()

"_selected" is the NodeProps instance that FlowCharter assigns to the PropertyGrid.SelectedObject property. So you just set its Text property along with the ShapeNode's Text. Note that _selected is Nothing when there isn't any selected diagram item.

I hope that helps,
Stoyan