WPF ListView Databound Drag/Drop Auto Scroll

Question

I\'ve been working with Bea\'s solution here for a while and finding it very helpful. Problem now I\'m having is when I drag-n-drop items within or to another ListView control

Answer 1

Another possibility to scroll is to use the ScrollBar-Commands. You can do this without climbing down the VisualTree. If you have a styles ListBox with no border the GetScrollViewer()-Method would not work anymore.

I use the first Element of the ItemContainerGenerator as CommandTarget for the ScrollBar.LineXXXCommand:

Point p = e.GetPosition(itemsControl);
  IInputElement commandTarget = itemsControl.ItemContainerGenerator.ContainerFromIndex(0) as IInputElement;

  if (commandTarget != null)
  {
    if (p.Y < OFFSET_TO_SCROLL)
      ScrollBar.LineUpCommand.Execute(null, commandTarget);
    else if (p.Y > itemsControl.ActualHeight - OFFSET_TO_SCROLL)
      ScrollBar.LineDownCommand.Execute(null, commandTarget);

    if (p.X < OFFSET_TO_SCROLL)
      ScrollBar.LineLeftCommand.Execute(null, commandTarget);
    else if (p.X > itemsControl.ActualWidth - OFFSET_TO_SCROLL)
      ScrollBar.LineRightCommand.Execute(null, commandTarget);
  }

Calling the LineXXXCommands is similiar to clicking the Arrow-Buttons of a ScrollBar: The ScrollViewer scrolles by a certain ammount which you can configure by setting the 'SmallAmount' Property of the ScrollBar.