Hi all,

My customer noticed something very strange... when he's got my application running, then clicks on the desktop (or runs another app from his task bar), then comes back to my application, the Drag/Drop event is firing.  I sprinkled the code with a few messages... 

long ll_form
string ls_title
long ll_ThisRow, ll_LastRow, ll_DropRow, ll_DragRow

MessageBox("DragDrop","Event fired")
ll_DragRow = this.GetSelectedRow(0)
MessageBox("DragDrop","Drag Row "+ string(ll_DragRow))
if (source.TypeOf() = DataWindow!) then
	drag_dw = source
//	 Make sure it's the same datawindow...
	if drag_dw.DataObject <> "d_salesorder_workorders" then 
		return
	end if
else
	return
end if

MessageBox("DragDrop", "DragObject = d_salesorder_workorders")
ll_DropRow = row
this.SetRedraw( FALSE )

MessageBox("DragDrop","DropRow: " + string(ll_DropRow))
CHOOSE CASE drag_dw
	CASE this
//		 If dropped on same row, don't do anything...
		if ll_DropRow = ll_DragRow then

			this.SetRedraw( TRUE )
			return
		end if

//		 Otherwise, change the line_nbr#'s and re-sort
		if ll_DropRow > ll_DragRow then
			ll_LastRow = ll_DropRow
			for ll_ThisRow = ll_DragRow + 1 to ll_DropRow
				this.SetItem(ll_ThisRow,"line_nbr",ll_ThisRow - 1)
			next
//				this.SetItem(ll_DragRow,"line_nbr",ll_ThisRow)
		else
			ll_LastRow = this.RowCount()
			for ll_ThisRow = ll_DropRow to ll_LastRow
				this.SetItem(ll_ThisRow,"line_nbr", ll_ThisRow + 1)
			next
//				this.SetItem(ll_DragRow,"line_nbr",ll_ThisRow)
		end if
		this.SetItem(ll_DragRow,"line_nbr",ll_DropRow)
		this.Sort()
		this.SetRow( ll_DropRow )
		this.SelectRow(0, FALSE)
		this.SelectRow(ll_DropRow, TRUE)

	CASE ELSE

For starters, this event shouldn't be firing at all, but it is.  The ll_DragRow is indeed the currently highlighted row.  The source is a DataWindow! with the DataObject = d_salesorder_workorders.  And ll_DropRow (row parameter from event) is the same as ll_DragRow.  There's a check to see if the ll_DragRow = ll_DropRow.  If so, don't do anything.  For some reason, the whole script is executing, and row 1 on the dw is being re-assigned to line_nbr 0 , row 2 is line_nbr 2, etc.  

What would cause the Drag/Drop event to fire when my app loses focus then regains focus? PB2021, PFC12.5, Windows 10 operating system.

~~~Tracy