//onLoad 裡

 wx.login({
      success(res) {
        console.log(res);
        var code = res.code
        var appid = '自己的appid'; 
        var appSecret = '自己的appSecret'
        wx.request({
          url: 'https://api.weixin.qq.com/sns/jscode2session?appid='+appid+'&secret='+appSecret+'&js_code='+code+'&grant_type=authorization_code',
          method: 
 
"post",
          // data: {
          //   code
          // },
          success: function (res) {
            console.log(res.data); 
            console.log(res.data.openid); 
            console.log(res.data.session_key); 
          }
        })
      }
    })

//Page 裡

getPhoneNumber: function (e) {
    
 
var that = this;
    console.log(e.detail.errMsg == "getPhoneNumber:ok");
    if (e.detail.errMsg == "getPhoneNumber:ok") {
　　　　//回撥函式
      wx.request({
        url: 'http://www.baidu.com',
        data: { },
        method: "post",
        success: function (res) {
          console.log(res);
        }
      })
    }
  },
 

//html 裡
<button open-type="getPhoneNumber" bindgetphonenumber="getPhoneNumber">獲取手機號</button>