微信小程序用户授权，以及判断登录是否过期的方法

<button bindtap="login">登录</button><button bindtap="checksession">登录是否过期</button><button open-type="getUserInfo" bindgetuserinfo="info">点击授权</button><text>{{city}}</text><text>{{country}}</text><text>{{nickName}}</text><text>{{province}}</text>

//index.js//获取应用实例const app = getApp() Page({ data: {  city:'',  country:'',  nickName:'',  province:'' }, //发起http请求 login:function(){  wx.login({   success:function(res){    console.log(res.code)    //发送请求    wx.request({     url: '自己的域名', //仅为示例，并非真实的接口地址     data: {      code:res.code     },     header: {      'content-type': 'application/json' // 默认值     },     success(res) {      console.log(res)     }    })   }  }) }, //验证登录是否过期 checksession:function(){  wx.checkSession({   success:function(res){    console.log(res,'登录未过期')    wx.showToast({     title: '登录未过期啊',    })   },   fail:function(res){    console.log(res,'登录过期了')    wx.showModal({     title: '提示',     content: '你的登录信息过期了，请重新登录',    })    //再次调用wx.login()    wx.login({     success: function (res) {      console.log(res.code)      //发送请求      wx.request({       url: '自己的域名', //仅为示例，并非真实的接口地址       data: {        code: res.code       },       header: {        'content-type': 'application/json' // 默认值       },       success(res) {        console.log(res)       }      })     }    })   }  }) }, //获取用户的信息 info:function(){  var that=this  wx.getUserInfo({   success:function(res){    console.log(res.userInfo)    var city = res.userInfo.city    var country = res.userInfo.country    var nickName = res.userInfo.nickName    var province = res.userInfo.province    that.setData({     city:city,     country:country,     nickName:nickName,     province:province    })   }  }) }})

<?php//声明code，用来接收前台传过来的code$code=$_GET['code']; //获取到appid$appid="xxxxxxxxxxx"; //自己的appid$secret="xxxxxxxxxxxx";  //自己的secret$api="https://api.weixin.qq.com/sns/jscode2session?appid={$appid}&secret={$secret}&js_code={$code}&grant_type=authorization_code";  //可去小程序开发文档中查看这个链接 //发送的代码function httpGet($url){	$curl=curl_init();	curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);	curl_setopt($curl, CURLOPT_TIMEOUT, 500);	curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, true);	curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, true);	curl_setopt($curl, CURLOPT_URL, $url);	$res= curl_exec($curl);	curl_close($curl);	return $res;} $str=httpGet($api); echo $str;?>