I just tried modifying the UpdateDemo sample, which already has two Diagrams in it.
I added a Palette in the XAML, some initialization code to give the palette two nodes, and added AllowDrop=“True” to both of the existing Diagrams. Here’s the initialization code I added:
myPalette.Model = new TestModel() {
NodesSource = new List<TestData>() {
new TestData() { Key="P1" },
new TestData() { Key="P2" }
}
};
Everything worked well.
Just in case there was a problem avoided because the two diagrams were sharing the same model, I also changed the second diagram to use its own model. Again, everything worked well.
Are you sure that the Palette.Model is using the same model class as the target Diagram.Model?
Silly me . By default I had set Diagram to use PanTool. And as known, PanTool doesn't allow you to add nodes to the diagram. Reverted back to the Default Tool, things are working fine.