Thank you for contacting Syncfusion Support.Query#1
:"determine when the user single clicks an item and which item they click os the view model run the command to open the file?"
We have prepared a sample with PinnableListBox .In this sample we have use ItemsSource to populate the items. While clicking the item, we have used command to display its header and Pinnable status.Query#2
:"determine when they click the item's pin to set its pin status?"
In this sample we have binded the “IsPinned” Property to the Tooltip of the item . This will display the Pinnable status .
Please download the sample from below.
Please let us know if you need further assistance.