WPF - Drag-drop - Adorner disappers outside the control - wpf

Question

I'm using WPF to create two ListViews and implement drag-drop functionality. (both intra-listview and inter-listview)
I found an interesting post here which does that.
However, there is a problem. When I drag a listviewitem from listView1, I see the adorner (the ghost image) only inside listView1. When I want to drop the listviewItem on ListView2, I must see the adorner there as well. Basically, the adorner appears only on the listView from which the drag operation started. Once it is outside the listView, it disappears.
I have done a bit of research and could not find a way to make the adorner visible outside the control from which the drag was initiated.
Can anyone help me with some suggestions?

Answer 1

Wire up the GiveFeedback event to update the adorner location beyond the listview. Updated ListView property from the example and method below (and in the listview_DragLeave method you won't want to collapse the adorner):
/// <summary>
/// Gets/sets the ListView whose dragging is managed. This property
/// can be set to null, to prevent drag management from occuring. If
/// the ListView's AllowDrop property is false, it will be set to true.
/// </summary>
public ListView ListView
{
get { return listView; }
set
{
if( this.IsDragInProgress )
throw new InvalidOperationException( "Cannot set the ListView property during a drag operation." );
if( this.listView != null )
{
#region Unhook Events
this.listView.PreviewMouseLeftButtonDown -= listView_PreviewMouseLeftButtonDown;
this.listView.PreviewMouseMove -= listView_PreviewMouseMove;
this.listView.DragOver -= listView_DragOver;
this.listView.DragLeave -= listView_DragLeave;
this.listView.DragEnter -= listView_DragEnter;
this.listView.GiveFeedback -= listView_GiveFeedback;
this.listView.Drop -= listView_Drop;
#endregion // Unhook Events
}
this.listView = value;
if( this.listView != null )
{
if( !this.listView.AllowDrop )
this.listView.AllowDrop = true;
#region Hook Events
this.listView.PreviewMouseLeftButtonDown += listView_PreviewMouseLeftButtonDown;
this.listView.PreviewMouseMove += listView_PreviewMouseMove;
this.listView.DragOver += listView_DragOver;
this.listView.DragLeave += listView_DragLeave;
this.listView.DragEnter += listView_DragEnter;
this.listView.GiveFeedback += listView_GiveFeedback;
this.listView.Drop += listView_Drop;
#endregion // Hook Events
}
}
}
void listView_GiveFeedback(object sender, GiveFeedbackEventArgs e)
{
if (this.ShowDragAdornerResolved)
this.UpdateDragAdornerLocation();
}