参考网址:http://greenrobot.org/eventbus/
引入EventBus:
compile 'org.greenrobot:eventbus:3.0.0'
1.快速入门
step1:定义事件
public class MessageEvent {
public final String message;
public MessageEvent(String message) {
this.message = message;
}
}
step2:接收并处理事件
相应生命周期方法中注册和解注册
@Override
public void onStart() {
super.onStart();
EventBus.getDefault().register(this);
}
@Override
public void onStop() {
EventBus.getDefault().unregister(this);
super.onStop();
}
定义处理事件方法
// This method will be called when a MessageEvent is posted (in the UI thread for Toast)
@Subscribe(threadMode = ThreadMode.MAIN)
public void onMessageEvent(MessageEvent event) {
Toast.makeText(getActivity(), event.message, Toast.LENGTH_SHORT).show();
}
// This method will be called when a SomeOtherEvent is posted
@Subscribe
public void handleSomethingElse(SomeOtherEvent event) {
doSomethingWith(event);
}
step3:发送事件
EventBus.getDefault().post(new MessageEvent("Hello everyone!"));
2.定义不同线程中处理事件
@Subscribe(threadMode = ThreadMode.POSTING) // 和发布者在同一个线程,默认的
public void onMessage(MessageEvent event) {
log(event.message);
}
// UI线程处理
@Subscribe(threadMode = ThreadMode.MAIN)
public void onMessage(MessageEvent event) {
textField.setText(event.message);
}
// 后台线程处理
@Subscribe(threadMode = ThreadMode.BACKGROUND)
public void onMessage(MessageEvent event){
saveToDisk(event.message);
}
// 单独的一个线程 线程池机制
@Subscribe(threadMode = ThreadMode.ASYNC)
public void onMessage(MessageEvent event){
backend.send(event.message);
}
3.Sticky Events 粘性事件
使用场景:例如想要在Activity初始化前发送事件在Activity启动后执行
发送一个粘性事件:EventBus.getDefault().postSticky(new MessageEvent("Hello everyone!"));
处理接收
@Override
public void onStart() {
super.onStart();
EventBus.getDefault().register(this);
}
@Subscribe(sticky = true, threadMode = ThreadMode.MAIN)
public void onEvent(MessageEvent event) {
// UI updates must run on MainThread
textField.setText(event.message);
}
@Override
public void onStop() {
EventBus.getDefault().unregister(this);
super.onStop();
}
获取或销毁粘性对象
MessageEvent stickyEvent = EventBus.getDefault().getStickyEvent(MessageEvent.class);
// Better check that an event was actually posted before
if(stickyEvent != null) {
// "Consume" the sticky event
EventBus.getDefault().removeStickyEvent(stickyEvent);
// Now do something with it
}
4.优先级
默认优先级是0 优先级越高先执行 不过不能影响不同线程之间的接收
@Subscribe(priority = 1);
public void onEvent(MessageEvent event) {
…
}
可以在高优先级截断低优先级的处理
@Subscribe
public void onEvent(MessageEvent event){
// Process the event
…
EventBus.getDefault().cancelEventDelivery(event) ;
}
5.混淆
-keepattributes *Annotation*
-keepclassmembers class ** {
@org.greenrobot.eventbus.Subscribe <methods>;
}
-keep enum org.greenrobot.eventbus.ThreadMode { *; }
# Only required if you use AsyncExecutor
-keepclassmembers class * extends org.greenrobot.eventbus.util.ThrowableFailureEvent {
<init>(java.lang.Throwable);
}