如何在适当的时候显示onbeforeunload对话框？ [英] How to display onbeforeunload dialog when appropriate?

问题描述

我的网页上有一个javascript编辑器，我想询问用户他/她是否想要离开页面，即使有未保存的更改。

I've got an editor in javascript on my webpage and I would like to ask user if he/she wants to leave the page even if there are unsaved changes.

我知道我可以通过这种方式向onbeforeunload对话框添加自定义消息：

I know I can add custom message to the "onbeforeunload dialog" this way:

window.onbeforeunload = function() {
  return 'You have unsaved changes!';
}

（ Source ）但是我想只显示一些未保存的更改的对话框。怎么做？

(Source) but I want to display the dialog only where there really are some unsaved changes. How to do that?

谢谢！

推荐答案

你可以做类似这样的事情：

You can do something like this:

var unsavedChanges = false;
window.onbeforeunload = function() {
  if (unsavedChanges) return 'You have unsaved changes!';
}

function makeSomeChange() {
  // do some changes....
  unsavedChanges = true;
}

您可以确保更改 unsavedChanges 在'change'事件处理程序中。

You can make sure to change unsavedChanges in the 'change' event handlers.

这篇关于如何在适当的时候显示onbeforeunload对话框？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！