C# WPF treeview双击上下左右箭头 反而触发了 treeview的双击事件

xaml中加入
<TreeView.ItemContainerStyle>
    <Style TargetType="{x:Type TreeViewItem}">
        <EventSetter Event="MouseDoubleClick" Handler="OnItemMouseDoubleClick" />
     
cs文件中 加入
 private void OnItemMouseDoubleClick(object sender, MouseButtonEventArgs args)
    {
        if (sender is TreeViewItem)
        {
            if (!((TreeViewItem)sender).IsSelected)
            {
                return;
            }
        }

        .... do stuff.

    }