//index.js

//获取应用实例

var app = getApp()

var temp_data;

Page({

  data: {

    items:[]

  },

  onLoad: function (e) {

   console.log(1)

    //页面初始化后发出新的请求

    wx.request({

      url: 'http://localhost:8000/API',

      data: {

      },

      method: 'GET',

      header: {

        'content-type': 'application/x-www-form-urlencoded'

      },

      success: function (res) {

        console.log(res.data.data)

        if (res.data.status == 1) {

          temp_data = res.data.data

        } else {

          wx.showToast({

           title: res.data.message,

            icon: 'loading',

            duration: 2000

          })

        }

      }

    })

  },

  onReady: function () {

    // 页面渲染完成

    this.setData({

      items:temp_data

    })

  },

})

报错，求解答Sat May 12 2018 23:22:43 GMT+0800 (中国标准时间) Setting data field "items" to undefined is invalid.