注册程序

App() 函数用来注册一个小程序。接受一个 object 参数，其指定小程序的生命周期函数等。App() 必须在 app.js 中注册，只能注册一个。使用this可以拿到app实例。

App({
  d: {
    token: 1,
    appId: " ",
    appKey: " ",
    hostUrl: 'http://xxx.com/',
    hostImg: ' http://xxx.com/upload/',  
  },

  onLaunch: function () {
    var that = this;
    //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);
    var token = wx.getStorageSync('token');
    that.d.token = token;
    if(!token){
      this.getUserInfo();
    }    
  },

  //登录并获取用户信息
  getUserInfo:function(cb){
    var that = this;
    if(this.globalData.userInfo){
      typeof cb == "function" && cb(this.globalData.userInfo);
      console.log(this.globalData.userInfo);
    }else{
      //调用登录接口获取登录凭证code
      wx.login({
        success: function (res) {
          var code = res.code;
          wx.getUserInfo({
            success: function (res) {
              that.globalData.userInfo = res.userInfo;
              console.log('以下是app.js从微信端获取的用户信息');
              console.log(res.userInfo);
              wx.setStorageSync('nickName', res.userInfo.nickName);
              wx.setStorageSync('avatarUrl', res.userInfo.avatarUrl);   
              wx.setStorageSync('city', res.userInfo.city);
              wx.setStorageSync('country', res.userInfo.country);   
              wx.setStorageSync('province', res.userInfo.province);   
              typeof cb == "function" && cb(that.globalData.userInfo);
              that.getUserSessionKey(code);
         
            }
          });
        }
      });
    }
  },

  //获取会话密钥
  getUserSessionKey:function(code){
    var that = this;
    wx.request({
      url: that.d.hostUrl+'public/wxAppUserCodeComes',
      method:'post',
      data: {
        code: code
      },
      header: {
        'Content-Type':  'application/x-www-form-urlencoded'
      },
      success: function (res) {      
        var userData = res.data.data;
        var userDataInfo = userData.user_info;
        console.log('以下是app.js用code换取了token 和open_id和session_key 如果绑定了还会返回user_name real_name等其他信息')
        console.log(userData);    //token   user_info{wx_app_open_id ，wx_app_session_key}
        var token = userData.token;  
        var userId= userDataInfo.wx_app_open_id
        //客户端存储token 
        wx.setStorageSync('token', token);
    
        if (!userId) {
          wx.showToast({
            title: '登录失败！',
            duration: 3000
          });
          return false;
        }
        that.d.token = token;
        that.onLoginUser();
      
      },
      fail:function(e){
        wx.showToast({
          title: '网络异常！err:getsessionkeys',
          duration: 2000
        });
      },
    });
  },

  //上传用户信息
  onLoginUser:function(){
    var that = this;
    var user = that.globalData.userInfo;
    var token = that.d.token;
    wx.request({
      url: that.d.hostUrl + 'public/updateWxUserInfo',
      method:'post',
      data: {
        token: token,
        nick_name: user.nickName,
        avatar_url: user.avatarUrl,
        gender:user.gender,   
        city:user.city,
        province: user.province,
        country:user.country,        
        language:user.language
      },
      header: {
        'Content-Type':  'application/x-www-form-urlencoded'
      },
      success: function (res) {    
        //console.log(res.data);   OK done:true
        console.log('以下是app.js上传用户信息后打印的全局用户数据');
        console.log(that.globalData.userInfo);
        var data = res.data;     
      },
      fail:function(e){
        wx.showToast({
          title: '网络异常！err:authlogin',
          duration: 2000
        });
      },
    });
  },

 globalData:{
    userInfo:null,
    products: [],
    carts:[]   
  },

  onPullDownRefresh: function (){
    wx.stopPullDownRefresh();
  }

});

小程序的生命周期函数

getApp()

全局的 getApp() 函数可以用来获取到小程序实例。

// other.js
var app = getApp()
console.log(app.globalData) // I am global data