onbeforeunload 在 codeigniter 中不起作用

Question

I have very simple code just to show a warning before page refreshed.我有非常简单的代码，只是为了在页面刷新之前显示警告。 The code uses Codeigniter as a framework (not sure if Codeigniter is related to the issue).该代码使用 Codeigniter 作为框架（不确定 Codeigniter 是否与该问题有关）。 I have a view file (test_v.php) with the following code:我有一个包含以下代码的视图文件（test_v.php）：

<?php ?>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>
<body >
<p>Test onbeforeunload</p>

<script type="text/javascript">
 window.onbeforeunload = function () {
  return 'Do you really want to perform the action?';
 }
</script>

</body>
</html>

Then I load this view file in a controller test.php $this->load->view('test_v');然后我将此视图文件加载到 controller test.php $this->load->view('test_v');

When I refresh the page, I expect to see a warning dialogue with the text 'Do you really want to perform the action?', but no warnings are shown at all.当我刷新页面时，我希望看到一个带有文本“您真的要执行该操作吗？”的警告对话框，但根本没有显示任何警告。 I have tested with IE, Firefox, Chrome.我已经用 IE、Firefox、Chrome 进行了测试。 None works.没有工作。 I have also tried adding the js code to the body label like this:我还尝试将 js 代码添加到正文 label 中，如下所示：

<body onbeforeunload=" return 'Do you really want to perform the action?'">

not working either.也不工作。 Could anyone help?有人可以帮忙吗？ Thanks a lot!非常感谢！

Answer 1

I suggest using as an event listener like this:我建议像这样用作事件侦听器：

window.addEventListener('beforeunload', function (e) {
  // Cancel the event
  e.preventDefault(); // If you prevent default behavior in Mozilla Firefox prompt will always be shown
  // Chrome requires returnValue to be set
  e.returnValue = '';
});

Per the MDN article :根据MDN 文章：

Note: To combat unwanted pop-ups, some browsers don't display prompts created in beforeunload event handlers unless the page has been interacted with.注意：为了防止不需要的弹出窗口，一些浏览器不显示在 beforeunload 事件处理程序中创建的提示，除非页面已经被交互。 Moreover, some don't display them at all.此外，有些根本不显示它们。

Might be the cause of your problem.可能是你的问题的原因。 I tested on a page and I didn't get the alert until interacted with the page.我在一个页面上进行了测试，直到与该页面交互后才收到警报。

onbeforeunload 在 codeigniter 中不起作用

问题描述

1 个解决方案

解决方案1
1 2020-12-02 01:32:16

onbeforeunload 在 codeigniter 中不起作用

问题描述

1 个解决方案

解决方案1 1 2020-12-02 01:32:16

解决方案1
1 2020-12-02 01:32:16