C#

// The Listbox Drop Event
private void commands_DragDrop(object sender, System.Windows.Forms.DragEventArgs e)
{
	Point here = commands.PointToClient(new Point(e.X, e.Y));
	string command = e.Data.GetData(DataFormats.Text).ToString();
	int location = commands.IndexFromPoint(here.X, here.Y);
	dragDropInProgress = false;
	dataNeedsSaving    = true;
	commands.Items.Insert(location, FormatedOutput(command, here));
	commands.SelectedIndex = -1;
	commands.SelectionMode = SelectionMode.MultiExtended;
	commands.SetSelected(location, true);
	Trace.WriteLine("Dropped "+command, "NavImport");
	e.Effect=DragDropEffects.Copy;
}
// The Listbox Dragover -- stops firing after one drop
private void commands_DragOver(object sender, System.Windows.Forms.DragEventArgs e)
{
        //This trace event is never seen after the drop occurs
	Trace.WriteLine(e.Data.GetDataPresent(DataFormats.Text).ToString() + ":" + commands.Items.Count, "NavImport");
	if (e.Data.GetDataPresent(DataFormats.Text) == false || commands.Items.Count == 0)
	{
		e.Effect = DragDropEffects.None;
		return;
	}
	e.Effect = DragDropEffects.Copy;
	dragDropInProgress = true;
	Point location = commands.PointToClient(new Point(e.X, e.Y));
	commands.SelectedIndex = -1;
	commands.SelectedIndex = commands.IndexFromPoint(location);
}

// The TreeView start of drag event always works
private void objectView_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
{
	Point here = new Point(e.X, e.Y);
	TreeNode drag = objectView.GetNodeAt(here);
	if (drag.Text.StartsWith(ParentNodeName))
		return;
	string command = "<" + drag.Parent.Text + ":" + drag.Text;
	objectView.DoDragDrop(command, DragDropEffects.Copy);
	Trace.WriteLine("Dragging "+command, "NavImport");
	commands.SelectedIndex = -1;
	commands.SelectionMode = SelectionMode.One;
	Trace.WriteLine("Current control state :"+commands.AllowDrop.ToString(), "NavImport");
}