void OnDrop(object sender, DragEventArgs e)
{
if (this.isDragging && e.Data.GetDataPresent(formatName))
{
object dragSource = e.Data.GetData(formatName);
if (dragSource != null)
{
DragDropTarget dropTarget = this.calledBackForValidatingTarget(dragSource, e.OriginalSource, e.Effects);
if (dropTarget != null)
{
if (dragSource != dropTarget.DataSource)
{
e.Handled = true;
UpdateEffects(e);
DestroyDragDropWindow();
this.calledBackFinalDropOperation(dragSource, dropTarget.DataSource, e.Effects);
}
}
}
}
DragDropRemoveAnyAdorner();
}
private bool UpdateEffects(DragEventArgs e)
{
if (!this.isDragging)
{
DragDropRemoveAnyAdorner();
e.Effects = DragDropEffects.None;
return(true);
}
object dragSource = e.Data.GetData(formatName);
if (dragSource == null)
{
DragDropRemoveAnyAdorner();
e.Effects = DragDropEffects.None;
return(false);
}
const int dragScrollMarginSpeedSlow = 30;
const int dragScrollMarginFast = 10;
Point pt = e.GetPosition(this.mainControl);
HitTestResult result = VisualTreeHelper.HitTest(this.mainControl, pt);
if (result != null)
{
if (pt.Y < dragScrollMarginSpeedSlow)
{
// The user is close to the bottom of the container (ListBox or TreeView)
if (pt.Y < dragScrollMarginFast)
{
AttemptToScrollUp(4);
}
else
{
AttemptToScrollUp(1);
}
}
else if (pt.Y > this.mainControl.ActualHeight - dragScrollMarginSpeedSlow)
{
// The user is close to the bottom of the container (ListBox or TreeView)
if (pt.Y > this.mainControl.ActualHeight - dragScrollMarginFast)
{
AttemptToScrollDown(4);
}
else
{
AttemptToScrollDown(1);
}
}
FrameworkElement ctrl = result.VisualHit as FrameworkElement;
if (ctrl != null)
{
DragDropTarget possibleDropTarget = this.calledBackForValidatingTarget(dragSource, ctrl, e.Effects);
if (possibleDropTarget != null && possibleDropTarget.DataSource != previousPossibleDropTarget)
{
if (possibleDropTarget.DataSource != dragSource)
{
DragDropRemoveAnyAdorner();
previousPossibleDropTarget = possibleDropTarget.DataSource;
this.adornerLayer = AdornerLayer.GetAdornerLayer(possibleDropTarget.TargetElement);
lastAdornerUsed = new AdornerDropTarget(possibleDropTarget.TargetElement);
this.adornerLayer.Add(lastAdornerUsed);
}
}
}
else
{
DragDropRemoveAnyAdorner();
}
}
else
{
DragDropRemoveAnyAdorner();
}
if (((e.AllowedEffects & DragDropEffects.Copy) == DragDropEffects.Copy) ||
((e.AllowedEffects & DragDropEffects.Move) == DragDropEffects.Move))
{
if ((e.KeyStates & DragDropKeyStates.ControlKey) == DragDropKeyStates.ControlKey)
{
e.Effects = DragDropEffects.Copy;
}
else
{
e.Effects = DragDropEffects.Move;
}
if (e.Effects != currentEffect)
{
currentEffect = e.Effects;
}
}
else
{
e.Effects = e.AllowedEffects & ((DragDropEffects.Copy | DragDropEffects.Move) ^ (DragDropEffects.All));
}
return(true);
}