Dev Express Treelist 同一个树上拖动 改变顺序

using DevExpress.XtraTreeList;

using DevExpress.XtraTreeList.Nodes;

private void treeList1_DragDrop(object sender, System.Windows.Forms.DragEventArgs e)
 {
    TreeListNode dragNode, targetNode;
    TreeList tl = sender as TreeList;
    Point p = tl.PointToClient(new Point(e.X, e.Y));
    dragNode = e.Data.GetData(typeof(TreeListNode)) as TreeListNode;
    targetNode = tl.CalcHitInfo(p).Node;
    tl.SetNodeIndex(dragNode, tl.GetNodeIndex(targetNode));
    e.Effect = DragDropEffects.None;
}