Winform递归绑定树节点

/// <summary>
/// 绑定树节点
/// </summary>
/// <param name="pid"></param>
/// <param name="treeNode"></param>
public void Band_TreeView(int pid,TreeNode treeNode)
{
string json = tree_helper.Get("Get?pid="+pid);
List<TreeViewModel> list = JsonConvert.DeserializeObject<List<TreeViewModel>>(json);
foreach (TreeViewModel item in list)
{
//实例化一个新的treenode
TreeNode tn = new TreeNode();
tn.Text = item.Tname;
tn.Tag = item.Id;  //控件的额外属性
//向总节点添加此节点
treeNode.Nodes.Add(tn);
//递归调用自身继续绑定
Band_TreeView(item.Id,tn);
}
}