异步创建树形菜单

[Table("userInfo")]
public class UserInfo
{
    [Key]
    public int Id { get; set; }
    [Required]
    [Index(IsUnique =true)]
    public string Username { get; set; }
    [Required]
    public string Password { get; set; }
    public string Acceuss { get; set; }
    public string Mobile { get; set; }
    public string Tel { get; set; }
}

<ul id="tt" class="easyui-tree" url="/User/TreeGetAccData"></ul>

public ActionResult TreeGetAccData()
{
    int id = Convert.ToInt32(Request.Form["id"]);
    //查找parentID=id的节点
    var accesses = from a in db.Accesses
                    where a.ParentAccessId == id
                    select a;


    List<object> list = new List<object>();
    foreach(var a in accesses)
    {
        list.Add(new { id = a.Id, text = a.Text, state = a.State, url = a.Url });
    }

    return Json(list);
}