Expand all row using binding

[peter]

In my case, I have a feature 'expand all'.  I binding IsExpandedProperty  for each row. the problem is when the object changed , there is only one row is expanded , the rest doesn't expand. Can you tell me how to slove this issure?

code for setbinding for each row
row.SetBinding(TreeListViewRow.IsExpandedProperty, new Binding("IsExpanded") { Source = row.DataContext, Mode = BindingMode.TwoWay });

thanks,

Jeff