对于类似的任务，可以使用sessionStorage在本地存储数据，直到关闭浏览器选项卡。

sessionStorage对象仅存储一个会话的数据(当浏览器选项卡关闭时，该数据将被删除)。

这是我的钢笔。

<div id="Notice">
    <span title="remove this until browser tab is closed"><u>dismiss</u>.</span>
</div>
<script>
    $("#Notice").click(function() {
     //set sessionStorage on click
        sessionStorage.setItem("dismissNotice", "Hello");
        $("#Notice").remove();
    });
    if (sessionStorage.getItem("dismissNotice"))
    //When sessionStorage is set Do stuff...
        $("#Notice").remove();
</script>

正如@jAndy提到的，没有合适的javascript代码来检测一个窗口正在关闭。 我从@Syno的提议开始。

我曾经遇到过类似的情况，只要你遵循这些步骤，你就能发现它。 我在Chrome 67+和Firefox 61+上进行了测试。

var wrapper = function () { //ignore this

var closing_window = false;
$(window).on('focus', function () {
    closing_window = false; 
   //if the user interacts with the window, then the window is not being 
   //closed
});

$(window).on('blur', function () {

    closing_window = true;
    if (!document.hidden) { //when the window is being minimized
        closing_window = false;
    }
    $(window).on('resize', function (e) { //when the window is being maximized
        closing_window = false;
    });
    $(window).off('resize'); //avoid multiple listening
});

$('html').on('mouseleave', function () {
    closing_window = true; 
    //if the user is leaving html, we have more reasons to believe that he's 
    //leaving or thinking about closing the window
});

$('html').on('mouseenter', function () {
    closing_window = false; 
    //if the user's mouse its on the page, it means you don't need to logout 
    //them, didn't it?
});

$(document).on('keydown', function (e) {

    if (e.keyCode == 91 || e.keyCode == 18) {
        closing_window = false; //shortcuts for ALT+TAB and Window key
    }

    if (e.keyCode == 116 || (e.ctrlKey && e.keyCode == 82)) {
        closing_window = false; //shortcuts for F5 and CTRL+F5 and CTRL+R
    }
});

// Prevent logout when clicking in a hiperlink
$(document).on("click", "a", function () {
    closing_window = false;
});

// Prevent logout when clicking in a button (if these buttons rediret to some page)
$(document).on("click", "button", function () {
    closing_window = false;

});
// Prevent logout when submiting
$(document).on("submit", "form", function () {
    closing_window = false;
});
// Prevent logout when submiting
$(document).on("click", "input[type=submit]", function () {
    closing_window = false;
});

var toDoWhenClosing = function() {

    //write a code here likes a user logout, example: 
    //$.ajax({
    //    url: '/MyController/MyLogOutAction',
    //    async: false,
    //    data: {

    //    },
    //    error: function () {
    //    },
    //    success: function (data) {
    //    },
    //});
};


window.onbeforeunload = function () {
    if (closing_window) {
        toDoWhenClosing();
    }
};

};

浏览器已经进行了更新，以便在用户离开应用程序时更好地调整用户。事件“visibilitychange”让你在页面从另一个选项卡隐藏或关闭时进行调整。您可以跟踪文档可见性状态。财产文件。visbilitystate将返回当前状态。您将需要跟踪标志的进出，但它更接近目标。

更新的浏览器支持这一点，但safari(正如我们所知)从来不符合标准。你可以使用' pagshow '和'pagehide'在safari中工作。

您甚至可以使用像sendBeacon这样的新API在标签关闭时向服务器发送单向请求，并且不应该期待响应。

我构建了一个类的快速端口，用于跟踪此情况。我不得不删除框架中的一些调用，所以它可能是bug，但这应该让你开始。

export class UserLoginStatus
{
    /**
     * This will add the events and sign the user in.
     */
    constructor()
    {
        this.addEvents();
        this.signIn();
    }

    /**
     * This will check if the browser is safari. 
     * 
     * @returns {bool}
     */
    isSafari()
    {
        if(navigator && /Safari/.test(navigator.userAgent) && /Chrome/.test(navigator.userAgent))
        {
            return (/Google Inc/.test(navigator.vendor) === false);
        }
        return false;
    }

    /**
     * This will setup the events array by browser.
     * 
     * @returns {array}
     */
    setupEvents()
    {
        let events = [
            ['visibilitychange', document, () =>
            {
                if (document.visibilityState === 'visible')
                {
                    this.signIn();
                    return;
                }

                this.signOut();
            }]
        ];

        // we need to setup events for safari
        if(this.isSafari())
        {
            events.push(['pageshow', window, (e) =>
            {
                if(e.persisted === false)
                {
                    this.signIn();
                }
            }]);

            events.push(['pagehide', window, (e) =>
            {
                if(e.persisted === false)
                {
                    this.signOut();
                }
            }]);
        }

        return events;
    }

    /**
     * This will add the events.
     */
    addEvents()
    {
        let events = this.setupEvents();
        if(!events || events.length < 1)
        {
            return;
        }

        for(var i = 0, length = events.length; i < length; i++)
        {
            var event = events[i];
            if(!event)
            {
                continue;
            }

            event[1].addEventListener(event[0], event[3]);
        }
    }

    /**
     * 
     * @param {string} url 
     * @param {string} params 
     */
    async fetch(url, params)
    {
        await fetch(url, 
        {
            method: 'POST',
            body: JSON.stringify(params)
        });
    }

    /**
     * This will sign in the user.
     */
    signIn()
    {
        // user is the app
        const url = '/auth/login';
        let params = 'userId=' + data.userId;

        this.fetch(url, params);
    }

    /**
     * This will sign out the user.
     */
    signOut()
    {
        // user is leaving the app

        const url = '/auth/logout';
        let params = 'userId=' + data.userId;

        if(!('sendBeacon' in window.navigator))
        {
            // normal ajax request here
            this.fetch(url, params);
            return;
        }

        // use a beacon for a more modern request the does not return a response
        navigator.sendBeacon(url, new URLSearchParams(params));
    }
}

onunload是Chrome的答案。根据caniuse它的交叉浏览器。但并非所有浏览器的反应都一样。

window.onunload = function(){
    alert("The window is closing now!");
}

developer.mozilla.org

这些事件在窗口卸载其内容和资源时触发。

铬:

Onunload只在页面关闭时执行。它甚至不会在页面刷新和导航到另一个页面时执行。

Firefox v86.0版本:

它根本不会执行。页面刷新，导航离开，关闭浏览器标签，关闭浏览器，什么都没有。

试试这个。它会起作用的。Jquery卸载方法。

window.onbeforeunload = function(event) {
    event.returnValue = "Write something clever here..";
};

如果我没说错，你想知道什么时候一个标签/窗口是有效关闭的。好吧，在JavaScript中检测这个的唯一方法是使用onunload或onbeforeunload事件。

不幸的是(或幸运的是?)，当您通过链接或浏览器的后退按钮离开网站时，这些事件也会被触发。这是我能给出的最好答案，我不认为你能在JavaScript中原生检测纯close。如果我说错了，请指正。