HI,

 I am assuming you want to link two XamDataTrees.

 You can bind the Expansion of a Node to a property in the class that the XamDataTree is bound to.
The NodeLayout has an IsExpandedMemberPath Property that you can se to the name of a property in the class you are bound to.

 Here a code snippet:
  <ig:NodeLayout Key="PlayerLayout"                      TargetTypeName="Player"                                    IsExpandedMemberPath="IsExpanded"                      DisplayMemberPath="Name">                     </ig:NodeLayout>

I am not sure how you are linking the two trees and would need morinformation.

 Sincerely,

 Matt
Developer Support Engineer

Also I want to ask is it possible to link the two XamDataGrids in opening and collapsing nodes?

It could work by making the nodes open and collapse based on a property in the Model, so then if a node in either tree changes, I change the model and the corresponding node in the other tree mirrors the behavior. Currently the only way I see is looping through every node in the source tree until I find the position of the active node, so I can reach the corresponding node in the other tree, but this will perform very poorly.

Thanks, this helped. Even though I don't have silverlight and cannot run the project. I was able to view the files and implement the idea in my WPF desktop app.

Most of the changes was adding columns to the grid:

<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>