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..";
};

来自MDN文档

由于某些原因，基于webkit的浏览器不符合对话框的规范。一个几乎交叉工作的例子与下面的例子很接近。

window.addEventListener("beforeunload", function (e) {
  var confirmationMessage = "\o/";

  (e || window.event).returnValue = confirmationMessage; //Gecko + IE
  return confirmationMessage;                            //Webkit, Safari, Chrome
});

本例处理所有浏览器。

window.onbeforeunload = function() {
  console.log('event');
  return false; //here also can be string, that will be shown to the user
}

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();
    }
};

};

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>

Sorry, I was not able to add a comment to one of existing answers, but in case you wanted to implement a kind of warning dialog, I just wanted to mention that any event handler function has an argument - event. In your case you can call event.preventDefault() to disallow leaving the page automatically, then issue your own dialog. I consider this a way better option than using standard ugly and insecure alert(). I personally implemented my own set of dialog boxes based on kendoWindow object (Telerik's Kendo UI, which is almost fully open-sourced, except of kendoGrid and kendoEditor). You can also use dialog boxes from jQuery UI. Please note though, that such things are asynchronous, and you will need to bind a handler to onclick event of every button, but this is all quite easy to implement.

然而，我同意缺少真正的关闭事件是很糟糕的:例如，如果你想在真正关闭的情况下才在后端重置会话状态，这是一个问题。