App({
  globalData: {
    nonetwork: false   //判断是否有网络
  },
  onShow() {
    this.onNetworkStatusChange()  //开启检测
  },
  onNetworkStatusChange() {
    var that = this
    //获取网络类型
    wx.getNetworkType({
      success: function (res) {
        const networkType = res.networkType
        //不为none代表有网络
        if ('none' != networkType) {
          that.globalData.nonetwork = true
          //网络状态变化事件的回调函数   开启网络监听，监听小程序的网络变化
          wx.onNetworkStatusChange(function (res) {
            if (res.isConnected) {
              //网络变为有网
              that.globalData.nonetwork = true
            } else {
              //网络变为无网
              that.globalData.nonetwork = false
            }
          })
        } else {
           //无网状态
          wx.onNetworkStatusChange(function (res) {
            if (res.isConnected) {
              that.globalData.nonetwork = true
            } else {
              that.globalData.nonetwork = false
            }
          })
        }
      },
    })
  }

})

const app = getApp()
Page({
  data: {
    nonetwork: false
  },
  onLoad() {
     //判断是否网络
    if (app.globalData.nonetwork) {
      this.setData({
        nonetwork: true
      })
      //添加转圈
      wx.showLoading({
        title: "获取数据中!"
      });
    } else {
      this.setData({
        nonetwork: false
      })
      wx.showToast({
        title: '请连接网络',
        icon: 'none',
        duration: 2000
      })
    }
  },
  doRefresh() {
    //无网络的刷新
    this.onLoad()
  }
})

<view wx:if="{{nonetwork}}">
  内容
</view>
<view wx:else>
  <button bindtap="doRefresh">刷新</button>
</view>