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
      }
  })
  