javascript 使用 onbeforeunload 函数内的自定义对话框确认重新加载页面。在弹出框之前在 onbeforeunload 函数中执行的代码
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/23679885/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Confirm reload page with a custom dialog box inside onbeforeunload function. Code to be executed in the function onbeforeunload before box popsup
提问by Harsha Rama
I want to show a confirm box when a user tries to reload a page. I have tried it in my project and it did not work. I have created a sample code of what i have tried and even it is not working. Can anybody tell where i have gone wrong. I am not even getting the confirm box. I am using Chrome 33+. I need to execute some code in the window.onbeforeunload before the box pops up.
当用户尝试重新加载页面时，我想显示一个确认框。我已经在我的项目中尝试过，但没有奏效。我已经创建了我尝试过的示例代码，但它甚至不起作用。谁能告诉我哪里出错了。我什至没有收到确认框。我正在使用 Chrome 33+。我需要在弹出框之前在 window.onbeforeunload 中执行一些代码。
<!DOCTYPE>
<html>
<body>
<script type="text/javascript">
window.onbeforeunload = function()
{
var r = confirm("Are you sure you want to reload the page.");
if(r)
{
window.location.reload();
}
else
{
}
};
</script>
</body>
</html>
回答by Jonast92
This will work:
这将起作用：
window.onbeforeunload = function ()
{
return "";
};
Recent versions of Chrome (and probably a few others) don't support anything but returning a simple message when using onbeforeunload. Other code in the function seems to be ignored, at least in Chrome.
Chrome 的最新版本（可能还有其他一些）在使用onbeforeunload. 函数中的其他代码似乎被忽略了，至少在 Chrome 中是这样。
Will do the trick for you. You can return something different (make it be custom) than the empty string but that will cause duplicate questions (your message + the one provided by the browser) but there's nothing stopping you from doing it.
会为你做的伎俩。您可以返回与空字符串不同的内容（使其成为自定义），但这会导致重复问题（您的消息 + 浏览器提供的消息），但没有什么可以阻止您这样做。
Tested in IE9 and newest version of Chrome. It will launch an alert box, asking whether the user wants to reload or not.
在 IE9 和最新版本的 Chrome 中测试。它将启动一个警告框，询问用户是否要重新加载。
