一、简介

官方介绍

EventBus: Events for Android

EventBus is an open-source library for Android using the publisher/subscriber pattern for loose coupling. EventBus enables central communication to decoupled classes with just a few lines of code – simplifying the code, removing dependencies, and speeding up app development.

EventBus Diagram

为应用程序中的各个组件（Activity, Fragment, Service等）提供了一个共享消息总线。

它们都可以注册接入消息总线，从而接收广播的消息，也可以往总线发消息。

二、上手

官方教程

1）Add EventBus as a dependency to your module.

compile 'org.greenrobot:eventbus:3.0.0'

2）Register Activity or Fragment to the event bus between onStart and onStop.

 @Override
 protected void onStart() {
      super.onStart();

      EventBus.getDefault().register(this);
 }

 @Override
 protected void onStop() {
      EventBus.getDefault().unregister(this);

      super.onStop();
 }

3）Define an Event class.

public class MessageEvent {
    private final String message;

    MessageEvent(String message) {
        this.message = message;
    }

    public String getMessage() {
        return message;
    }
}

4）Add event listener functions with annotation @Subscribe .

 @Subscribe(threadMode = ThreadMode.MAIN)
 public void onMessageEvent(MessageEvent event) {
      Log.d(TAG, "onMessageEvent " + event.getMessage());
      textView.setText(TAG + " " + event.getMessage());
 }

 @Subscribe
 public void onYAMessageEvent(MessageEvent event) {
      Log.d(TAG, "onYAMessageEvent " + event.getMessage());
 }

5）Post event from anywhere.

EventBus.getDefault().post(new MessageEvent(message));

详见官方文档。有问题欢迎回帖交流。