- 关于EventBus
implementation 'org.greenrobot:eventbus:3.0.0'
2.2）定义一个类，用户数据传输中间件
public class MessageEvent{
private String message;
publicMessageEvent(String message){
this.message=message;
}
public String getMessage() {
return message;
}
public void setMessage(String message) {
this.message = message;
【EventBus使用】}
}
2.3）在一个Activity中，注册Event
EventBus.getDefault().register(this)
2.4）在同一个类中 做一个Subscribe,就是订阅，其实就是接收数据
@Subscribe(threadMode = ThreadMode.MAIN)
Public void receiveMsg(MessageEvent messageEvent){
Tv_event.setText(messageEvent.getMessage());
}
2.5）EventBus应该随着Activity的销毁而销毁
protected void onDestroy() {
super.onDestroy();
EventBus.getDefault().unregister(this);
}
2.5）在另外一个Activity中把这个Message发送出来
EventBus.getDefault().post(new MessageBus(“this is message”));
ThreadMode.POSTING ThreadMode.MAIN 是可以更新UI
ThreadMode.BACKGROUNDThreadMode.ASYNC 是在线程中的（不能更新UI），但是我操作为什么线程中能更新UI了，难道是post()不放到Thread中，更新bakground async更新UI有问题，但是如果post放到Thread中，ui能更新？
public class MyEventMainActivity extends Activity implements View.OnClickListener {
TextView tv_eventmsg_posting;
TextView tv_eventmsg_main;
TextView tv_eventmsg_BACKGROUND;
TextView tv_eventmsg_ASYNC;
Button btn_registevent;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setContentView(R.layout.activity_myevent_main);
initView();
registerEvent();
}
private void initView() {
tv_eventmsg_posting = this.findViewById(R.id.tv_eventmsg_posting);
tv_eventmsg_main = this.findViewById(R.id.tv_eventmsg_main);
tv_eventmsg_BACKGROUND = this.findViewById(R.id.tv_eventmsg_BACKGROUND);
tv_eventmsg_ASYNC = this.findViewById(R.id.tv_eventmsg_ASYNC);
btn_registevent = this.findViewById(R.id.btn_registevent);
btn_registevent.setOnClickListener(this);
}
/**
* 注册event
*/
private void registerEvent(){
EventBus.getDefault().register(this);
}
/**
* 接收messageEvent
* @param messageEvent
*/
//@Subscribe(threadMode = ThreadMode.MAIN)
//@Subscribe(threadMode = ThreadMode.POSTING)
@Subscribe(threadMode = ThreadMode.POSTING)
public void recieveEventMsgPosting(MessageEvent messageEvent){
tv_eventmsg_posting.setText("POSTING:"+messageEvent.getMessage());
}
@Subscribe(threadMode = ThreadMode.MAIN)
public void recieveEventMsgMain(MessageEvent messageEvent){
tv_eventmsg_main.setText("main:"+messageEvent.getMessage());
}
@Subscribe(threadMode = ThreadMode.BACKGROUND)
public void recieveEventMsgBackground(MessageEvent messageEvent){
tv_eventmsg_BACKGROUND.setText("background:"+messageEvent.getMessage());
}
@Subscribe(threadMode = ThreadMode.ASYNC)
public void recieveEventMsgAsync(MessageEvent messageEvent){
tv_eventmsg_ASYNC.setText("async:"+messageEvent.getMessage());
}
@Override
public void onClick(View v) {
if(v.getId()==R.id.btn_registevent){
Intent intent = new Intent(this,MessagePublishActivity.class);
this.startActivity(intent);
}
}
@Override
protected void onDestroy() {
super.onDestroy();
EventBus.getDefault().unregister(this);
}
}
public class MessagePublishActivity extends Activity implements View.OnClickListener {Button btn_publishevent; Button btn_publishevent_thread; @Overrideprotected void onCreate(@Nullable Bundle savedInstanceState) {super.onCreate(savedInstanceState); this.setContentView(R.layout.activity_messagepublish); initView(); }private void initView() {btn_publishevent = this.findViewById(R.id.btn_publishevent); btn_publishevent_thread = this.findViewById(R.id.btn_publishevent_thread); btn_publishevent.setOnClickListener(this); btn_publishevent_thread.setOnClickListener(this); }@Overridepublic void onClick(View v) {if(v.getId() == R.id.btn_publishevent){EventBus.getDefault().post(new MessageEvent("我是 event 发布者，也就是发送者")); finish(); }else if(v.getId() == R.id.btn_publishevent_thread){new Thread(new Runnable() {@Overridepublic void run() {EventBus.getDefault().post(new MessageEvent("我是 event 发布者，也就是发送者thread")); finish(); }}).start(); }}}
