[RESOLVED] Event for Detecting Failed Drag/Drop

[neef]

In my application code is executed during drag/drop which draws pretty cool looking x's across controls that won't accept a drop. Everything works fine if the drag/drop is succesful because i erase the x's in the dragdrop event, but if the user lets go of the left mouse button over a control which doesn't accept a drop then the x's stay on the screen I need an event which is triggered if the drag drop fails. I tried using a simple mouseup event for the entire form but it hasn't worked for some reason.

Any help would be appreciated. Thanx!

[jmcilhinney]

I've not done a lot of drag-n-drop so I'm no expert but I'd start by looking at the GiveFeedback and QueryContinueDrag events to see whether they might be of use. That said, can you not just handle DragDrop for those other controls and perform the cleanup without performing the drop?

[neef]

Finally got back to this issue and wanted to report that jmcilhinney's suggested event QueryContinueDrag was the best option for my situation. I also added some code (borrowed from another site) that handled if the user moves the mouse off the form.

Private Sub UCHeadCoachSchedule_QueryContinueDrag(ByVal sender As System.Object, ByVal e As System.Windows.Forms.QueryContinueDragEventArgs) Handles MyBase.QueryContinueDrag  'Other dragdrop controls

        Dim lb As CCTrainingLabel = CType(sender, CCTrainingLabel)
        If (lb IsNot Nothing) Then

            Dim f As Form = Me.FindForm

            ' Cancel the drag if the mouse moves off the form or drops outside a eligible control
            If Control.MousePosition.X < f.DesktopBounds.Left Or Control.MousePosition.X > f.DesktopBounds.Right Or Control.MousePosition.Y < f.DesktopBounds.Top Or Control.MousePosition.Y > f.DesktopBounds.Bottom Or Control.MouseButtons = Windows.Forms.MouseButtons.None Then
                e.Action = DragAction.Cancel
                ' Other cleanup code
             End If
        End if
End Sub