text: //app.js
  App({
  	onLaunch: function () {
  		//调用API从本地缓存中获取数据
  		var logs = wx.getStorageSync('logs') || []
  		logs.unshift(Date.now())
  		wx.setStorageSync('logs', logs)
  	},
  
  	getUserInfo: function (cb) {
  		var that = this
  		if (this.globalData.userInfo) {
  			typeof cb == "function" && cb(this.globalData.userInfo)
  		} else {
  			//调用登录接口
  			wx.login({
  				success: function () {
  					wx.getUserInfo({
  						success: function (res) {
  							that.globalData.userInfo = res.userInfo
  							typeof cb == "function" && cb(that.globalData.userInfo)
  						}
  					})
  				}
  			})
  		}
  	},
  	
  	globalData: {
  		userInfo: null
  	}
  })