I need to execute a piece of code when the user is grouping the rows by doing drag & drop of a column to the area "Drag a column header here to group by that column". What is the event for that?
It is very urgent.
Use Before/AfterSortChanged.
maybe do "InitializeGroupByRow"
but it don't call, then you have one column in area "Drag a column ..." and you drag this column back to grid.