如何在javascript中更改beforeunload事件

Question

Is calling an ajax function possible before someone's decide to leave the page. 是否可以在有人决定离开页面之前调用ajax函数。 I mean i can ask the user if user wants to leave or stay. 我的意思是我可以问用户是否要离开或停留。 But i dont know how to alter behaviour when user click "yes leave the page" button. 但是当用户单击“是，离开页面”按钮时，我不知道如何更改行为。

I have this code working.. 我有这个代码工作..

<head>
<script type="text/javascript">
    function catchExit() {
        return "All your data is going to be lost. Are you sure??";
    }
</script>
</head>
<body onbeforeunload="return catchExit()">
<p>
    Dont leave the page.
</p>
</body>

Answer 1

Here's an alternative way using confirm : 这是使用confirm的另一种方法：

function catchExit(){
  var exit = confirm("Are you sure?");
  if (exit){
  }
}

But keep in mind that AJAX can't stop the thread. 但是请记住，AJAX无法停止线程。 That means that there's no guarantee the call: 这意味着无法保证调用：

Makes it 使它
Is successful 成功了
Returned a result 返回结果

The window will have shown the prompt and/or exited before the AJAX may have even completed. 在AJAX可能尚未完成之前，该窗口将显示提示和/或退出。 To illustrate it better: 为了更好地说明它：

function catchExit(){
  $.ajax({
    success: function(){
      // this is an entirely new thread and returning a result
      // has ZERO effect on the original catchExit function
      // (And chances are it's already executed and is long gone)
    }
  });
  // this (99.99% of the time) will be called long before
  // 'success' above is called, therefore making 'success' and its
  // outcome moot.
  return "There are unsaved changes, are you sure you want to exit?";
}

Answer 2

Actually, i found a way to get my $.ajax() call worked. 实际上，我找到了一种使$.ajax()调用起作用的方法。 Setting async parameter to false works in firefox, chrome, iexplorer and safari. 将async参数设置为false可以在Firefox，Chrome，iexplorer和Safari中使用。 It only doesn't work in opera. 它仅在歌剧中不起作用。

如何在javascript中更改beforeunload事件

问题描述

2 个解决方案

解决方案1
1 2012-08-18 12:52:34

解决方案2
0 已采纳 2012-08-20 16:17:25

如何在javascript中更改beforeunload事件

问题描述

2 个解决方案

解决方案1 1 2012-08-18 12:52:34

解决方案2 0 已采纳 2012-08-20 16:17:25

解决方案1
1 2012-08-18 12:52:34

解决方案2
0 已采纳 2012-08-20 16:17:25