IntentSvice和Service的区别

首先IntentService是继承自Service的，那我们先看看Service的官方介绍，这里列出两点比较重要的地方：

1.A Service is not a separate process. The Service object itself does not imply it is running in its own process; unless otherwise specified, it runs in the same process as the application it is part of.

2.A Service is not a thread. It is not a means itself to do work off of the main thread (to avoid Application Not Responding errors).

稍微翻一下(英文水平一般)

1.Service不是一个单独的进程 ，它和应用程序在同一个进程中。

2.Service不是一个线程，所以我们应该避免在Service里面进行耗时的操作

关于第二点我想说下，不知道很多网上的文章都把耗时的操作直接放在Service的onStart方法中，而且没有强调这样会出现Application Not Responding！希望我的文章能帮大家认清这个误区(Service不是一个线程，不能直接处理耗时的操作)。

有人肯定会问，那么为什么我不直接用Thread而要用Service呢？关于这个，大家可以网上搜搜，这里不过多解释。有一点需要强调，如果有耗时操作在Service里，就必须开启一个单独的线程来处理！！！这点一定要铭记在心。

IntentService相对于Service来说，有几个非常有用的优点，首先我们看看官方文档的说明：

IntentService is a base class for Services that handle asynchronous requests (expressed as Intents) on demand. Clients send requests throughstartService(Intent) calls; the service is started as needed, handles each Intent in turn using a worker thread, and stops itself when it runs out of work.

This "work queue processor" pattern is commonly used to offload tasks from an application's main thread. The IntentService class exists to simplify this pattern and take care of the mechanics. To use it, extend IntentService and implement onHandleIntent(Intent). IntentService will receive the Intents, launch a worker thread, and stop the service as appropriate.

All requests are handled on a single worker thread -- they may take as long as necessary (and will not block the

application's main loop), but only one request will be processed at a time

自己写了一个 测试 直接用Service 中写了一个耗时操作 居然进程没挂掉 ，，，用IntentService 写的进程居然挂掉了。。很纠结