get3rdSession: function () {
  let that = this
  wx.request({
   url: 'https://localhost/login.php',
   data: {
    code: this.data.code
   },
   method: 'GET', // OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, CONNECT
   success: function (res) {
    var sessionId = res.data;
    that.setData({ sessionId: sessionId })
    wx.setStorageSync('sessionId', sessionId)
    that.decodeUserInfo()
   }
  })
 },
 decodeUserInfo: function () {
  let that = this
  wx.request({
   url: 'https://localhost/decrypt.php',
   data: {
    encryptedData: that.data.encryptedData,
    iv: that.data.iv,
    session: wx.getStorageSync('sessionId')
   },
   method: 'GET', // OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, CONNECT
   // header: {}, // 设置请求的 header
   success: function (res) {
    let todayStep = res.data.stepInfoList.pop()
    that.setData({
     step: todayStep.step
    });
   }
  })
 },
 onLoad: function () {
  let that = this
  wx.login({
   success: function (res) {
    let code = res.code
    that.setData({ code: code })
    wx.getWeRunData({//解密微信运动
     success(res) {
      const wRunEncryptedData = res.encryptedData
      that.setData({ encryptedData: wRunEncryptedData })
      that.setData({ iv: res.iv })
      that.get3rdSession()//解密请求函数
     }
    })
   }
  })
 }

$appid = '你的appid';
$appsecret = '你的appsecret';

$url = 'https://api.weixin.qq.com/sns/jscode2session?appid='.$appid.'&secret='.$appsecret.'&js_code='.$_GET['code'].'&grant_type=authorization_code';

$content = file_get_contents($url);
$content = json_decode($content);
echo $content->session_key;

$pc = new WXBizDataCrypt($appid, $sessionKey);
$errCode = $pc->decryptData($encryptedData, $iv, $data );

if ($errCode == 0) {
  print($data . "\n");
} else {
  print($errCode . "\n");
}