How can I get the result of my javascript from webview through EvaluateJavaScriptAsync?

[IShiraiKurokoI]

I tried the following code to get info from the page automatically

        void EleInfo_Navigated(object sender, WebNavigatedEventArgs e)
        {
            if (int.Parse(DateTime.Now.Hour.ToString()) <= 1 || int.Parse(DateTime.Now.Hour.ToString()) >= 23)
            {
                ElectricityInfo.Text = "Can't query now!";
                return;
            }
            if (url.IndexOf("homerj") !=-1&&url.IndexOf("api")==-1)
            {
                ElectricityInfo.Text = "Loading  page。。。";
                EleInfo.EvaluateJavaScriptAsync("window.location.href='https://example.com/elepay/openElePay?openid='+openid[0].value+'&displayflag=1&id=30'");
            }
            if(url.IndexOf("openElePay")!=-1)
            {
                ElectricityInfo.Text = "Loading completed, start querying。。。";
                EleInfo.EvaluateJavaScriptAsync(Properties.Resources.Send);
                EleInfo.EvaluateJavaScriptAsync(Properties.Resources.Eleget);
                EleInfo.EvaluateJavaScriptAsync("getinfo()");
                ElectricityInfo.IsVisible = false;
            }
        }

As I'm going to receive the result of EleInfo.EvaluateJavaScriptAsync("getinfo()"); I tried Console.WriteLine(await EleInfo.EvaluateJavaScriptAsync("getinfo()")); But nothing was write on the console. I was used to use window.chorme.webview.postmessage in webview2 on WPF.

The javascript I have used:
Properties.Resources.Send:

function send(eleinfo) {
    var url = "/business/queryResEleByIdserial";
    var param = new Object();
    param.idserial = $("#idserial").val();
    param.xqh = $("#xqh").val();
    dkyw.request.post(url, param, function(data){
        if(data&&data.success){
            var data1 = data.resultData;
            if ("E001" == $("#factorycode").val() || "E002" == $("#factorycode").val()) {
                $("#roombalance").val(dkywcommon.fenToYuan(dkywcommon.yuanToFen(data1.sydl)));
				console.log('寝室电费：'+dkywcommon.fenToYuan(dkywcommon.yuanToFen(data1.sydl)));
				return '寝室电费：'+dkywcommon.fenToYuan(dkywcommon.yuanToFen(data1.sydl))
            }else if ("E003" == $("#factorycode").val()){
                var syld=data1.sydl;
                var sylds=syld.split("/");
                var room =sylds[0];
                var living=sylds[1];
                $("#roombalance").val("房间："+parseInt(room)+"，客厅："+parseInt(living));
				console.log('寝室电费：'+"房间："+parseInt(room)+"，客厅："+parseInt(living));
				return '寝室电费：'+"房间："+parseInt(room)+"，客厅："+parseInt(living)
            }
        }else{
            $("#roombalance").val("");
            mh_dialogShow('mh_warning', queryI18n(data.message), 3, true);
        }
        queryBuildingList(eleinfo);
    });
}

Properties.Resources.Eleget:

function getinfo() {
  $("#factorycode").val('E001');
  $("#xqh").val('03');
  var url = "/business/queryEleInfoByIdserial";
  var param = new Object();
  param.idserial = $("#idserial").val();
  param.xqh = $("#xqh").val();
  dkyw.request.post(url, param, function (data) {
    if (data && data.success) {
      var resultData = data.resultData;
      if (dkywcommon.isEmpty(resultData.jzwbh)) {} else if (dkywcommon.isEmpty(resultData.fjlc)) {} else if (dkywcommon.isEmpty(resultData.fjmc)) {

      } else {
        if (resultData.xqh == '01') {
          $("#factorycode").find("option[value='E002']").prop("selected", true);
        } else if (resultData.xqh == '03') {
          $("#factorycode").find("option[value='E001']").prop("selected", true);
        } else if (resultData.xqh == '02') {
          $("#factorycode").find("option[value='E003']").prop("selected", true);
        } else {
          return;
        }

        var factorycode = $("#factorycode").val();
        var eleinfo = new Object();
        eleinfo.buildingid = resultData.loudongid;
        eleinfo.floorid = resultData.fjlc;
        eleinfo.roomid = resultData.roomid; //房间ID
        eleinfo.roomname = resultData.fjmc; //房间名称
        if (resultData.xqh == "02") { //盘锦校区存在房间或者客厅用户自选
          eleinfo.livingid = resultData.livingid;
        }
        if (factorycode != 'E002') {
          $("#floorid").parent().hide();
        }
        //获取该证件号对应的房间余额
        return send(eleinfo);
      }
    } else {
      $("#factorycode").val('E002');
      $("#xqh").val('01');
      var url = "/business/queryEleInfoByIdserial";
      var param = new Object();
      param.idserial = $("#idserial").val();
      param.xqh = $("#xqh").val();
      dkyw.request.post(url, param, function (data) {
        if (data && data.success) {
          var resultData = data.resultData;
          if (dkywcommon.isEmpty(resultData.jzwbh)) {

          } else if (dkywcommon.isEmpty(resultData.fjlc)) {

          } else if (dkywcommon.isEmpty(resultData.fjmc)) {

          } else {
            if (resultData.xqh == '01') {
              $("#factorycode").find("option[value='E002']").prop("selected", true);
            } else if (resultData.xqh == '03') {
              $("#factorycode").find("option[value='E001']").prop("selected", true);
            } else if (resultData.xqh == '02') {
              $("#factorycode").find("option[value='E003']").prop("selected", true);
            } else {
              return;
            }

            var factorycode = $("#factorycode").val();
            var eleinfo = new Object();
            eleinfo.buildingid = resultData.loudongid;
            eleinfo.floorid = resultData.fjlc;
            eleinfo.roomid = resultData.roomid; //房间ID
            eleinfo.roomname = resultData.fjmc; //房间名称
            if (resultData.xqh == "02") { //盘锦校区存在房间或者客厅用户自选
              eleinfo.livingid = resultData.livingid;
            }
            if (factorycode != 'E002') {
              $("#floorid").parent().hide();
            }
            //获取该证件号对应的房间余额
            return send(eleinfo);
          }
        } else {
          $("#factorycode").val('E003');
          $("#xqh").val('02');
          var url = "/business/queryEleInfoByIdserial";
          var param = new Object();
          param.idserial = $("#idserial").val();
          param.xqh = $("#xqh").val();
          dkyw.request.post(url, param, function (data) {
            if (data && data.success) {
              var resultData = data.resultData;
              if (dkywcommon.isEmpty(resultData.jzwbh)) {

              } else if (dkywcommon.isEmpty(resultData.fjlc)) {

              } else if (dkywcommon.isEmpty(resultData.fjmc)) {

              } else {
                if (resultData.xqh == '01') {
                  $("#factorycode").find("option[value='E002']").prop("selected", true);
                } else if (resultData.xqh == '03') {
                  $("#factorycode").find("option[value='E001']").prop("selected", true);
                } else if (resultData.xqh == '02') {
                  $("#factorycode").find("option[value='E003']").prop("selected", true);
                } else {
                  return;
                }

                var factorycode = $("#factorycode").val();
                var eleinfo = new Object();
                eleinfo.buildingid = resultData.loudongid;
                eleinfo.floorid = resultData.fjlc;
                eleinfo.roomid = resultData.roomid; //房间ID
                eleinfo.roomname = resultData.fjmc; //房间名称
                if (resultData.xqh == "02") { //盘锦校区存在房间或者客厅用户自选
                  eleinfo.livingid = resultData.livingid;
                }
                if (factorycode != 'E002') {
                  $("#floorid").parent().hide();
                }
                //获取该证件号对应的房间余额
                return send(eleinfo);
              }
            } else {}
          });
        }
      });
    }
  });
}