微信小程序loading组件如何载入动画方法教程

<loading> 加载中...</loading><button>点击弹出loading</button>

Page({  data: {    loadingHidden: true  },  loadingTap: function(){    this.setData({     loadingHidden: false    });    var that = this;    setTimeout(function(){     that.setData({       loadingHidden: true     });     that.update();    }, 3000);  }})