1. Guide package

compile 'org.greenrobot:eventbus:3.0.0'

2. Add confusion

-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);
}

3. The first activity

public class MainActivity extends AppCompatActivity {
    TextView textView;
    TextView kaiqi;
    Button sub;
    Button tiao;
    int tag = 0;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        textView = (TextView) findViewById(R.id.show);
        textView.setText("mainactivity");
        kaiqi = (TextView) findViewById(R.id.kaiqi);
        sub = (Button) findViewById(R.id.sub);
        tiao = (Button) findViewById(R.id.tiao);

        tiao.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(MainActivity.this , Activity2.class));
            }
        });

        sub.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (tag == 0) {
                    EventBus.getDefault().register(MainActivity.this);
                    kaiqi.setText("EventBus registered subscription");
                    tag = 1;
                } else if (tag == 1){
                    EventBus.getDefault().unregister(MainActivity.this);
                                         kaiqi.setText("EventBus cancel registration subscription");
                    tag = 0;
                }

            }
        });
    }

    @Subscribe(threadMode = ThreadMode.MAIN)
         public void onMoonEvent(Message msg) {//Receive the message published by the publisher
        if (msg.what == 1) {
            String lr = (String) msg.obj;
            textView.setText(lr);
        }

    }

         @Subscribe(threadMode = ThreadMode.POSTING, sticky = true) //sticky sticky event, you can subscribe later to view the news published by the publisher first
    public void onMoonStickyEvent(Message msg){
                 int waht = msg.what; //If there are more eventbus, you can use msg.what to judge and distinguish the eventbus you want to specify
        if (waht == 2) {
            textView.setText(msg.obj.toString());
        }
    }


    @Override
    protected void onDestroy() {
        super.onDestroy();
        EventBus.getDefault().unregister(MainActivity.this);
    }

}

4. The second activity

public class Activity2 extends AppCompatActivity {
    TextView show;
    Button fa;
    Button nian;
    int i = 0;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_2);

        show = (TextView) findViewById(R.id.show2);
        show.setText("activity2");
        fa = (Button) findViewById(R.id.famsg2);
        nian = (Button) findViewById(R.id.nianx);

        fa.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Message msg = new Message();
                msg.what = 1;
                                 msg.obj = "Welcome to my blog";
                EventBus.getDefault().post(msg);
                finish();
            }
        });

        nian.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Message msg = new Message();
                msg.what = 2;
                                 msg.obj = "This is a sticky event";
                EventBus.getDefault().postSticky(msg);
                finish();
            }
        });
    }
}

5. Simple functions are achieved