I have a XamDataGrid that is bound to a dataset with multiple parent-child tables. This particular dataset has Expression fields in nearly every table that perform counting and sums. Each row acts as a toggle switch that turns an artificial selection flag on / off . When clicking on a row very quickly, the row's parent sometimes collapses for no apparent reason. Sometimes another unrelated parent collapses for no apparent reason. I am trying to better understand why this would happen but the first trick is to catch the send of the collapse in the act... So, how do I detect a row collapse?