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开源框架 —> EventBus 消息总线框架使用
1. 前言
OTA模块用到消息总线框架EventBus，经过对比handler,项目中消息比较多，使用EventBus框架，便于统一管理
EventBus是一款针对Android优化的发布/订阅事件总线。主要功能是替代Intent,Handler,BroadCast在Fragment，Activity，Service，线程之间传递消息.优点是开销小，代码更优雅。以及将发送者和接收者解耦
EventBus 框架类库 Github
源码：https://github.com/greenrobot/EventBus
2. 实战
2.1 基本使用方法
(1) 自定义一个消息类
public class MyEventBus{
public static final int JUMP_TO_NETWORKSETTINGS = 0x01;
public static final int RETURN_TO_SECONDPAGER = 0x02;
private String message;
private int what;
public MessageEvent(String message) {
this.message = message;
}
public MessageEvent(int what) {
this.what = what;
}
public MessageEvent(String message, int what) {
this.message = message;
this.what = what;
}
public String getMessage() {
return message;
}
public void setMessage(String message) {
this.message = message;
}
public int getWhat() {
return what;
}
public void setWhat(int what) {
this.what = what;
}
}
(2) 接受消息的界面注册与反注册，以及接收消息后实现
//OnCreate函数中注册EventBus
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//注册EventBus
EventBus.getDefault().register(this);
}
//OnDestory函数中反注册EventBus
@Override
protected void onDestroy() {
//反注册EventBus
EventBus.getDefault().unregister(this);
super.onDestroy();
}
//接收消息后的实现，4种不同的实现方法，根据项目实际需要选取
@Subscribe(threadMode = ThreadMode.MAIN)
public void onMessageEvent(MessageEvent event) {/* Do something */};
(3) 发送消息
//发送消息界面无需注册于反注册
EventBus.getDefault().post(new MyEvent("EventBus first Msg!!!"));
ThreadMode 四种线程实现控制
1. ThreadMode: POSTING
// Called in the same thread (default)（与Post保持一致的线程）
// ThreadMode is optional here
@Subscribe(threadMode = ThreadMode.POSTING)
public void onMessage(MessageEvent event) {
log(event.message);
}
2. ThreadMode: MAIN
// Called in Android UI's main thread(UI 线程)
@Subscribe(threadMode = ThreadMode.MAIN)
public void onMessage(MessageEvent event) {
textField.setText(event.message);
}
3. ThreadMode: BACKGROUND
// Called in the background thread（post 主线程，新开线程接收消息，post非主线程，使用post线程）
@Subscribe(threadMode = ThreadMode.BACKGROUND)
public void onMessage(MessageEvent event){
saveToDisk(event.message);
}
4. ThreadMode: ASYNC
// Called in a separate thread（直接新开线程）
@Subscribe(threadMode = ThreadMode.ASYNC)
public void onMessage(MessageEvent event){
backend.send(event.message);
}
参考Github 开发描述：http://greenrobot.org/eventbus/documentation/delivery-threads-threadmode/
