/// <summary>
/// 在将对象拖入控件的边界时发生。
/// </summary>
private void treeView_DragEnter(object sender, DragEventArgs e)
{
DragHelper.ImageList_DragEnter(this.tempTreeView.Handle, e.X - this.tempTreeView.Left, e.Y - this.tempTreeView.Top);
this.timer.Enabled = true;
}
