I haven’t seen that error in years, since when we were implementing undo/redo support long before we first released any version of GoDiagram.
It’s likely the error is occuring in some implementation of GoObject.ChangeValue, as an undo is being performed on a GoChangedEventArgs. Can you narrow down the kind of operation that you are undoing?
this.Changed(0, 0, 0, this.Bounds, 0, 0, this.Bounds);
this.Text = dlg.NodeName;
this.Label.TextColor = dlg.NodeColor;
this.Label.Font = dlg.NodeFont;
this.Description = dlg.NodeDescription;
this.Document.FinishTransaction("Node properties changed");
I haven’t tried that code, but that call to Changed(0, …) looks suspicious. Try removing that line.
What class is this code defined in? What version of GoDiagram Win(?) are you using?
Well, you must be referring to the Description property, which I assume is something you defined. Then the error is raised by GoObject.ChangeValue, when it sees a hint value that it doesn’t recognize.
You just need to override ChangeValue to handle your particular “ChangedDescription” hint case. There are lots of examples of this in the sample applications.