有人可以告诉我在 TRUE 的区别？

Can someone tell me the TRUE difference?

推荐答案

我的经验法则是，一个的AsyncTask 是当我想要做的事情依赖于单一的活动和服务是当我想要做一些东西，开始是在活动结束后，将进行以背景。

My rule of thumb is that an AsyncTask is for when I want to do something tied to single Activity and a Service is for when I want to do something that will carry on after the Activity which started it is in the background.

所以，如果我想要做的后台处理的活动小一点不占用我会用UI中的的AsyncTask 。然后，我将使用默认的处理程序从活动来传递讯息传回，以确保更新发生在主线程。处理主线程上的更新有两个好处：用户界面更新发生正确，你不必太担心同步问题

So if I want to do a small bit of background processing in the Activity without tying up the UI I'll use an AsyncTask. I'll then use the default Handler from that Activity to pass messages back to ensure updates happen on the main thread. Processing the updates on the main thread has two benefits: UI updates happen correctly and you don't have to worry so much about synchronisation problems.

如果举例来说，我想做一个下载可能需要一段时间，我会使用一个服务。所以，如果我去了另一个活动在我的应用程序或其他应用程序完全是我的服务可以继续运行，并保留下载文件所以这将是准备当我回到了我的申请。在这种情况下，我可能会使用一个状态栏通知一次下载完成，因此用户可以选择回到我的应用程序，只要是方便了他们。

If for example, I wanted to do a download which might take a while I'd use a Service. So if I went to another Activity in my application or another application entirely my Service could keep running and keep downloading the file so it would be ready when I returned to my application. In this case I'd probably use a Status Bar Notification once the download was complete, so the user could choose to return to my application whenever was convenient for them.

什么，你会发现，如果你使用的AsyncTask 对于长时间运行的过程中，它可能会继续你的活动导航离开后， 但是：

What you'll find if you use an AsyncTask for a long-running process it may continue after you've navigated away from the Activity but:

如果在活动是在后台，当你处理完毕，你可能会遇到问题，当您尝试的结果等更新UI。 系统背景活动更有可能被机器人杀死时，它需要的内存比一个服务。 If the Activity is in the background when your processing is complete you may have problems when you try to update the UI with the results etc. A background Activity is far more likely to be killed by Android when it needs memory than a Service.