javascript 是否可以以编程方式触发 onbeforeunload 事件？
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Is it possible to trigger the onbeforeunload event programmatically?
提问by mutex
I'm currently using the jquery-form-observeplugin which uses onbeforeunload to prompt the user about "unsaved" changes.
我目前正在使用jquery-form-observe插件，它使用 onbeforeunload 来提示用户有关“未保存”的更改。
But I have a scenario where I need to trigger this on a button click: the button click ultimately leads to the page changing, but I want to prompt the user before they start the process that the button click kicks off...
但是我有一个场景，我需要在单击按钮时触发它：单击按钮最终会导致页面更改，但我想在用户开始按钮单击开始的过程之前提示用户...
So is there a way to trigger onbeforeunload through jQuery or otherwise?
那么有没有办法通过jQuery或其他方式触发onbeforeunload？
采纳答案by casablanca
I don't know if there is a direct way to do this, but you could always emulate the browser's confirmation box yourself. Here's a simple function I cooked up based on the specs at MSDN:
我不知道是否有直接的方法可以做到这一点，但您始终可以自己模拟浏览器的确认框。这是我根据MSDN上的规范编写的一个简单函数：
function triggerBeforeUnload() {
var event = {};
handler(event);
if (typeof event.returnValue == 'undefined' ||
confirm('Are you sure you want to navigate away from this page?\n\n' + event.returnValue + '\n\nPress OK to continue, or Cancel to stay on the current page.')) {
// Continue with page unload
} else {
// Cancel page unload
}
}
Edit:In jquery.formobserver.js, right after the definition of function beforeunload(e) { ... }, add this line:
编辑：在 中jquery.formobserver.js，在 定义之后function beforeunload(e) { ... }，添加这一行：
handler = beforeunload;
Note the change in the original code: window.onbeforeunloadhas been replaced by handler.
注意原代码的变化：window.onbeforeunload已被替换为handler.
回答by Pat
You can do it with the .trigger()method:
你可以用.trigger()方法做到这一点：
$('button').click(function(){
$(window).trigger('beforeunload');
});
