ASP.net核心Window.Onunload无法正常工作

Question

我在视图内部处理了一些signalR消息。该处理程序使用window.open（）打开一个新窗口。当该窗口关闭时，我需要处理一些事情。我在窗口上使用.onunload（），以便在关闭时可以处理某些事情。我注意到.onunload（）在打开窗口后立即被击中，这没有任何意义，应该在关闭窗口时将其关闭。这是我正在使用的代码：

        connection.on("ProcessStartEnvironmentReply", (env) =>
        {
            var url = env.url + '/#/?username=' + env.username + '&password=' + env.password;
            environmentId = env.environmentID;

            console.log("Start reply msgid: " + env.sourceMessageId + ", env: " + environmentId + " at " + new Date());

            arenaWin = window.open(url, '_blank');

            arenaWin.onbeforeunload = function ()
            {
                return "Do you really want to close?";
            };
            arenaWin.onunload = function ()
            {
                //TODO: This log message is getting hit as soon as the tab is opened, not useful until fixed.
                console.log("CLOSING TAB ------------------");

                //$.ajax({
                //    url: '/api/dashboard/stop/' + environmentId,
                //    type: "GET",
                //    dataType: "JSON",
                //    success: function (env) {
                //        $("#btnStart").attr("disabled", false);
                //        console.log(env);
                //    }
                //});
            };

            arenaWin.addEventListener('unload', function (e)
            {
                var confirmationMessage = "--------------------\o/----------------------";
                console.log("CLOSING TAB EVENT ADDED");
                (e || window.event).returnValue = confirmationMessage; //Gecko + IE
                return confirmationMessage;
            });

        });

有人遇到这样的事情吗？