微權獲取openid信授

（1）首頁要有一個本身的微信測試號的appid和祕鑰
（2）公司裏都是後臺傳code（接口），獲取openid（接口）
請求code接口：/Wechat/GetUserInfo/getCode
//判斷是不是移動設備打開
    function Isweixin(){
        var userAgentInfo = navigator.userAgent.toLowerCase();
        // var demainUrl ='http://faw-vw.ftms-wechat.com';
        var returnUrl =chineseTransfer(window.location);
        if (userAgentInfo.match(/MicroMessenger/i) == "micromessenger") {
            var code = getUrlParam("code");
            if (!code) {
                window.location = "/Wechat/GetUserInfo/getCode?callbackurl="+returnUrl;
            }else{
                getOpenId(code);
            }
        }else {
            //網頁打開的
            // window.location = demainUrl+"/Wechat/GetUserInfo/getCode?callbackurl="+returnUrl;
            window.location = "/Wechat/GetUserInfo/getCode?callbackurl="+returnUrl;
        }
    }

    //獲取code
    function getUrlParam(name) {
        var reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)");
        var r = window.location.search.substr(1).match(reg);
        if (r != null) return unescape(r[2]);
        return null;
    }

// 請求openid
getOpenId = function (code) {
    $.ajax({
        type: 'POST',
      	url:"/Wechat/GetUserInfo/getUserInfo"，
        data: { code: code },
        success: function (res) {
             var data = res.data;
             console.log(data);
            var param = {
                    ass_openid :data.openid,
                    ass_name :data.nickname,
                    ass_head_img : data.headimgurl
            };
            localStorage.setItem("fromOpenid",param.ass_openid);
    });
}