自定义控件绑定XML显示不出来，datasource的Item里面有数据

XML：部分<?xml version="1.0" encoding="utf-8" ?>
<menu>
  <menuItem>
    <text>用户管理</text>
    <roles>1</roles>
    <subMenu>
      <menuItem>
        <text>添加用户</text>
        <url>admin_UserAdd.aspx</url>
        <target>mainFrame</target>
      </menuItem>
      <menuItem>
        <text>用户列表</text>
        <url>admin_UserList.aspx</url>
        <target>mainFrame</target>
      </menuItem>    </subMenu>
  </menuItem>
  <menuItem>
    <text>角色管理</text>
    <roles>2</roles>
    <subMenu>
      <menuItem>
        <text>角色分类管理</text>
        <url>admin_RoleClass.aspx</url>
        <target>mainFrame</target>
      </menuItem>
      <menuItem>
        <text>角色列表</text>
        <url>admin_Role.aspx</url>
        <target>mainFrame</target>
      </menuItem>
      <menuItem>
        <text>角色权限管理</text>
        <url>admin_RolePermission.aspx</url>
        <target>mainFrame</target>
      </menuItem>
    </subMenu>
  </menuItem>
  <menuItem>
    <text>权限管理</text>
    <roles>2</roles>
    <subMenu>
      <menuItem>
        <text>权限分类管理</text>
        <url>admin_PermissionClass.aspx</url>
        <target>mainFrame</target>
      </menuItem>
      <menuItem>
        <text>权限管理</text>
        <url>admin_Permission.aspx</url>
        <target>mainFrame</target>
      </menuItem>
    </subMenu>
  </menuItem>
</menu>数据绑定：
  private void BindMenu()
        {            Account.Bus.AccountsPrincipal user = (Account.Bus.AccountsPrincipal)(Session["UserRoleAndPermiison"]);
            ArrayList roleCodeList = user.RolesCode;            for (int i = 0; i < roleCodeList.Count; i++)
            {
                this.Menu.UserRoles.Add(roleCodeList[i].ToString());
            }
            this.Menu.DataSource = Server.MapPath("../Admin/AdminMenu.xml");
            this.Menu.DataBind();
        }