WPF 中设置TreeView的默认展开深度、展开所有节点

前端代码 

<TreeView
    Name="MyTreeView"
    MouseDoubleClick="MyTreeView_MouseDoubleClick"
    VirtualizingPanel.IsVirtualizing="True"
    />

后台代码

 // 在加载TreeView时调用该方法
 private void InitializeTreeView()
 {

     for (int i = 0; i < MyTreeView.Items.Count; i++)
     {
         TreeViewItem item = MyTreeView.Items[i] as TreeViewItem;
         if (item != null && item.HasItems)
         {
             ExpandTreeViewItems(item, 2); // 设置默认展开的节点深度为2
             //ExpandTreeViewItems(item); // 设置默认展开所以节点
         }
     }
    
 }

 /// <summary>
 /// 展开指定深度
 /// </summary>
 /// <param name="item"></param>
 /// <param name="depth"></param>
 private void ExpandTreeViewItems(TreeViewItem item, int depth)
 {
     if (depth > 0)
     {
         item.IsExpanded = true;
         for (int i = 0; i < item.Items.Count; i++)
         {
             TreeViewItem Titem = item.Items[i] as TreeViewItem;
             if (Titem != null)
             {
                 ExpandTreeViewItems(Titem, depth-1); 
             }
         }
         
     }
 }

 /// <summary>
 /// 展开所有节点
 /// </summary>
 /// <param name="item"></param>
 private void ExpandTreeViewItems(TreeViewItem item)
 {
     
     item.IsExpanded = true;
     for (int i = 0; i < item.Items.Count; i++)
     {
         TreeViewItem Titem = item.Items[i] as TreeViewItem;
         if (Titem != null)
         {
             ExpandTreeViewItems(Titem);
         }
     }

 }