In order to attach a global handler for all clicks in the RadBreadCrumb, you can use the AddHandler() method.
In the handler itself you will be able to check the e.OriginalSource property
sender, RoutedEventArgs e)
The code inside the if statement will be triggered when the user clicks on the toggle button and you will be allowed to fetch the data.
For your convenience I prepared sample project demonstrating this approach. Please take a look at it and let me know if you need any further assistance.
Pavel R. Pavlov
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