将服务绑定到 FragmentActivity 还是 Fragment? [英] Bind service to FragmentActivity or Fragment?

问题描述

服务绑定到FragmentActivity是否更好:

bindService(Intent, ServiceConnection, int);

或Fragment:

getActivity().bindService(Intent, ServiceConnection, int);

什么是更好的做法?

推荐答案

将服务绑定到 FragmentActivity... 还是绑定到 Fragment

Is it better to bind service to FragmentActivity... or to Fragment

它们与您在此处写的相同.getActivity() 不是 Fragment —— 它是一种返回 Activity 的方法.您不能在 Fragment 上调用 bindService().

They are the same as you have them written here. getActivity() is not a Fragment -- it is a method that returns the Activity. You cannot call bindService() on a Fragment.

什么是更好的做法?

都没有.绑定到通过 getApplicationContext() 获得的 Application 对象，ServiceConnection 由(或者实际上被管理)) 一个保留的Fragment.

Neither. Bind to the Application object, obtained via getApplicationContext(), with the ServiceConnection managed by (or perhaps actually being) a retained Fragment.

原因是配置更改.绑定是状态.您需要在配置更改时保持该状态.虽然保留的 Fragment 可以保留 ServiceConnection，但系统中 ServiceConnection 和 Context 之间存在隐式联系code> 将其注册为绑定.由于 Activity 可以在配置更改时被销毁和重新创建，因此 Activity 在这里不是 Context 的好选择.Application 是系统全局的，是一个更安全的选择，并且选择 Application 而不是另一个 Context 是明智之举的少数地方之一恕我直言.

The reason is configuration changes. A binding is state. You need to maintain that state across configuration changes. While a retained Fragment can hold onto the ServiceConnection, there is an implicit tie in the system between the ServiceConnection and the Context that registered it for a binding. Since activities can be destroyed and recreated on configuration changes, the Activity is not a good choice of Context here. Application, which is system-global, is a safer choice, and one of the few places where choosing Application over another Context is a wise move IMHO.

这是我的一篇博文，来自在碎片之前的时间，这更深入一点.这是一个示例项目，演示了该技术.

Here is a blog post of mine, from a time before fragments, that gets into this a bit more. Here is a sample project demonstrating the technique.

这篇关于将服务绑定到 FragmentActivity 还是 Fragment?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！