为什么我用了wx.getShareInfo返回解密后没有openGId，只有如下json

{"openId":null,"nickName":null,"gender":null,"city":null,"province":null,"country":null,"avatarUrl":null,"unionId":null,"watermark":{"appid":"XXX","timestamp":"1534411759"}}

app.js代码如下

App({

onLaunch: function (options) {

//this.checkLogin(options.shareTicket);  

this.globalData.shareInfo = null;

if (options.scene == 1044) {

that.getShareInfo(options.shareTicket);

}

},

onShow: function (options) {

this.checkLogin(options.shareTicket);

},

checkLogin: function (shareTicket) {

var that = this;

wx.checkSession({

success: function () {

if (!that.globalData.session) {

that.login(shareTicket);

}

else

{

if (shareTicket) {

that.getShareInfo(shareTicket);

}

};

},

fail: function () {

that.login(shareTicket);

}

})

},

//登录  

login: function (shareTicket) {

var that = this

wx.login({

success: function (r) {

if (r.code) {

that.decodeSession(r.code, shareTicket);

}

wx.getUserInfo({

success: function (res) {

that.globalData.userInfo = res.userInfo;

}

})

}

})

},

//解密session信息  

decodeSession: function (code, shareTicket) {

var that = this;

wx.request({

url: 'https://weixin.wlstock.com/Haogudao/GetOpenIdByCode',//向后端发起换取session_key请求的URL  

data: {

code: code

},

success: function (re) {

if (re.data != null && re.data.openid != null && re.data.openid != '') {

that.globalData.session = {

openid: re.data.openid,

key: re.data.session_key

};

if (shareTicket) {

that.getShareInfo(shareTicket);

}

}

else {

that.globalData.session = null;

}

},

fail: function (res) {

console.log(res);

}

})

},

//获取群信息  

getShareInfo: function (shareTicket) {

var that = this;

console.log('去获取getShareInfo');

wx.getShareInfo({

shareTicket: shareTicket,

success: function (res) {

console.log('去获取shareinfo');

wx.request({

url: that.globalData.APIUrl +'/DataHandle/Decrypt',//向后端发起解密请求的URL  

data: {

encryptStrOfBase64: res.encryptedData,

encryptSessionKey: that.globalData.session.key,

iv: res.iv

},

success: fun