在Dart M8中卸载前提醒 [英] Alert before unload in Dart M8

问题描述

在dart里程碑8之前，不可能通过以下方法提醒用户离开页面：

As of dart milestone 8, it is not possible to alert the user before (s)he navigates away from the page by the following method:

window.onBeforeUnload.listen((BeforeUnloadEvent event) {
    event.returnValue = 'Are you sure you want to leave?';
});

，因为Event.returnValue字段已删除。
如何使用新的API实现这个效果？

since the Event.returnValue field has been removed. How do you accomplish this effect with the new API?

这是如何使用jQuery：

This is how it's done with jQuery:

$(window).on('beforeunload', function(){
  return 'Are you sure you want to leave?';
});

推荐答案

新的Blink版本 - Blink最终本地添加了BeforeUnloadEvent。在此之前，我们必须伪造它。

It looks like the API got dropped when we integrated a new Blink version- Blink finally added the BeforeUnloadEvent natively. Prior to that we had to fake it.

查看错误 https://code.google.com/p/dart/issues/detail?id=14641

解决方法：像以前一样使用它。传入的事件是BeforeUnloadEvent的子类，并且仍然具有returnValue。

Workaround: use it just as before. The event being passed in is a subclass of BeforeUnloadEvent and still has returnValue.

这篇关于在Dart M8中卸载前提醒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！