如何在mdl菜单中显示动态值

<button id="menu-button" class="mdl-button mdl-js-button mdl-button--icon">
  <i class="material-icons">more_vert</i>
</button>

<ul class="mdl-menu mdl-js-menu mdl-js-ripple-effect" for="menu-button">
  <!-- 菜单项 -->
</ul>

var dynamicValue = "动态值";

var menu = document.querySelector('.mdl-menu');
var menuItem = document.createElement('li');
menuItem.classList.add('mdl-menu__item');
menuItem.innerHTML = dynamicValue;

menu.appendChild(menuItem);

var menuButton = document.querySelector('#menu-button');
componentHandler.upgradeElement(menuButton, 'MaterialButton');

var menu = document.querySelector('.mdl-menu');
componentHandler.upgradeElement(menu, 'MaterialMenu');