动态生成树

if (!IsPostBack) //如果是第一次加载页面
{
   if (Session["TreeNod"] == null) //如果不存在菜单树缓存对象
   {
      BuildTreeview(); //调用生成菜单树
      if (tvNavigation.Nodes.Count > 0)
      {
         Session["TreeNod"] = tvNavigation.Nodes[0]; //将生成的菜单树缓存
      }
   }
   else //如果存在菜单树缓存对象
   {
      //从缓存对象中取出菜单树
      TreeNode Nod = (TreeNode)(Session["TreeNod"]);
      tvNavigation.Nodes.Add(Nod);
   }
}

#region 生成菜单树相关方法

/// <summary>
/// 递归生成菜单树
/// </summary>
private void BuildTreeview()
{
    tvNavigation.Nodes.Clear();
   string conStr = ConfigurationManager.ConnectionStrings["ExpatiateAspNetConnectionString1"].ToString();
   DataClassesDataContext dc = new DataClassesDataContext(conStr);
   List<MenuInfo> menuList = dc.MenuInfo.Select(itm=>itm).ToList();
   List<MenuInfo> level1List = menuList.Where(itm => itm.MenuLevel == 1).ToList();
   foreach (MenuInfo level1 in level1List)
   {
      TreeNode nod = GetTreeNode(level1);
      BuildTreeNode(level1, nod, menuList);
      tvNavigation.Nodes.Add(nod);
    }

}

/// <summary>
/// 递归实现函数
/// </summary>
/// <param name="curNod"></param>
/// <param name="menuList"></param>
private void BuildTreeNode(MenuInfo menu, TreeNode nod, List<MenuInfo> menuList)
{
   List<MenuInfo> childMenuList = menuList.Where(itm => itm.ParentNode == menu.MenuCode).ToList();
   foreach (MenuInfo childMenu in childMenuList)
   {
      TreeNode childNod = GetTreeNode(childMenu);//调用自定义方法GetTreeNode获得节点对象
      nod.ChildNodes.Add(childNod);//将节点对象添加到TreeView控件中
      BuildTreeNode(childMenu, childNod, menuList);
   }
}

/// <summary>
/// 根据菜单实体生成树节点实体
/// </summary>
/// <param name="menu"></param>
/// <returns></returns>
private TreeNode GetTreeNode(MenuInfo menu)
{
   TreeNode nod = new TreeNode();
   nod.Value = menu.MenuID.ToString();//设置节点值属性
   nod.NavigateUrl = menu.Url; //设置节点的导航URL
   nod.Text = menu.Title; //设置节点显示的标题
   nod.ToolTip = menu.Description; //设置节点描述信息
   nod.Target = menu.Target;
   nod.ImageUrl = menu.ImgUrl; //设置节点左侧显示的图标
   return nod;
}

#endregion