public static void OnDragEnter(TreeViewItemEx tvItem, DragEventArgs e)
{
System.Diagnostics.Debug.WriteLine($"DragEnter: {tvItem.Item}");
if (dropInfo == null)
{
dropInfo = new DropInfo();
}
if (dropInfo.CouldHadleDrop(e))
{
dropInfo.TargetItem = tvItem;
e.Handled = true;
}
OnDragOver(tvItem, e);
}
public static void OnDragOver(TreeViewItemEx tvItem, DragEventArgs e)
{
//System.Diagnostics.Debug.WriteLine($"DragOver: {tvItem.Item}");
if (dropInfo == null)
{
dropInfo = new DropInfo();
}
if (dropInfo.CouldHadleDrop(e))
{
// set the target item, this also initializes the DropTargetAdorner
dropInfo.TargetItem = tvItem;
// update data related to the current mouse position and the target item
dropInfo.UpdateInsertPosition(e);
dropInfo.UpdateTargetContainerAndIndex();
// set the drop mode Copy|Move|None
if (dropInfo.CanAcceptData(DropInfo.ExtractDropData(dragInfo, e)))
{
if ((Keyboard.Modifiers & ModifierKeys.Control) == ModifierKeys.Control)
{
e.Effects = DragDropEffects.Copy;
}
else
{
e.Effects = DragDropEffects.Move;
}
}
else
{
e.Effects = DragDropEffects.None;
}
// this controls the adorner
dropInfo.Effects = e.Effects;
e.Handled = true;
}
}