EventBus

###EventBus中文注解。个人对EventBus源码的阅读理解。

说明和看法
- 目前为止对于register, unRegister, post中涉及到的类和重要方法都做了注释，有很深刻的认识。比如post的线程调度，注册函数是如何通过反射找到的等等流程
- EventBus一般在用的时候我们一般直接getDefault，其实可以通过EventBusBuilder这个类进行链式操作来构造EventBus实例，具体请自己查看源码。很重要的一个变量就是ignoreGeneratedIndex，如果你通过new EventBusBuilder().ignoreGeneratedIndex(true);这个对象来去构造EventBus，那么EventBus不会通过反射去得到注册函数，而是通过编译时期的注解处理器去获得信息。具体代码请查看SubscriberMethodFinder类。
- 虽然EventBus会默认通过反射获得注册函数，但是获取一次之后会缓存在一个map里面，所以不会每一次都去通过反射去获得注册函数
- 可以很明显的看到EventBus对于扩展性，框架设计做的一些操作。并且代码简单易懂，不会像系统源码那样一个类就几千行。还是很值得阅读的入门级别的源码。

EventBus is a publish/subscribe event bus optimized for Android.

EventBus...

simplifies the communication between components
- decouples event senders and receivers
- performs well with Activities, Fragments, and background threads
- avoids complex and error-prone dependencies and life cycle issues
makes your code simpler
is fast
is tiny (~50k jar)
is proven in practice by apps with 100,000,000+ installs
has advanced features like delivery threads, subscriber priorities, etc.

EventBus in 3 steps

Define events:
public class MessageEvent { /* Additional fields if needed */ }
Prepare subscribers
Register your subscriber (in your onCreate or in a constructor):
eventBus.register(this);

Declare your subscribing method:
@Subscribe
public void onEvent(AnyEventType event) {/* Do something */};
Post events:
eventBus.post(event);

This getting started guide shows these 3 steps in more detail.

Please ensure that you are using the latest version by checking here

Gradle:

    compile 'org.greenrobot:eventbus:3.0.0'

Maven:

<dependency>
    <groupId>org.greenrobot</groupId>
    <artifactId>eventbus</artifactId>
    <version>3.0.0</version>
</dependency>

For more details on EventBus please check EventBus' website. Here are some direct links you may find useful:

How does EventBus compare to other solutions, like Otto from Square? Check this comparison.

EventBus binaries and source code can be used according to the Apache License, Version 2.0.

greenrobot-common is a set of utility classes and hash functions for Android & Java projects.

greenDAO is an ORM optimized for Android: it maps database tables to Java objects and uses code generation for optimal speed.