有什么用例，没有UI中的片段？ [英] What is the use case for a Fragment with no UI?

问题描述

Android开发指南对使用碎片一个体面的部分。使用片段的方法之一是没有的UI。有几个参考使用此作为后台处理的手段，但是优势并片段为这一领域？我会在哪里选择使用片段在线程，AsyncTasks，处理程序等，为后台处理？

The Android Developer guide has a decent section on the use of Fragments. One way to use Fragments is without a UI. There are a few references to using this as a means of background processing, but what advantages do Fragments bring to this area? Where would I choose to use a Fragment over Threads, AsyncTasks, Handlers, etc. for background processing?

推荐答案

A 片段实例可以通过设备配置变化（如屏幕旋转）依然存在。因为一个活动将被销毁并重新创建时，配置的变化情况，这是很难设计之一，将跟踪线程或的AsyncTask 。在另一方面，该系统需要重新连接照顾一个持续片段到正确的活动在另一端（所以说话）的配置变化。你仍然可以使用线程或的AsyncTask ，只是现在的片段拿着它来代替。

A Fragment instance can persist through device configuration changes (like screen rotation). Because an Activity will be destroyed and recreated when a configuration change happens, it's difficult to design one that will keep track of a thread or AsyncTask. On the other hand, the system takes care of reattaching a persisted Fragment to the proper Activity at the other end (so to speak) of the configuration change. You would still be using a thread or AsyncTask, only now the Fragment is holding it instead.

可能还有其他用途，但有一个我能想到的。

There may be other uses for it, but there's the one I can think of.

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