EventBus是針一款對Android的釋出/訂閱事件匯流排。它可以讓我們很輕鬆的實現在Android各個元件之間傳遞訊息，並且程式碼的可讀性更好，耦合度更低。

依賴：compile ‘org.greenrobot:eventbus:3.0.0’

• 1.1MainAcivity主方法

public class MainActivity extends AppCompatActivity {

    //註解
    @ViewInject(R.id.onbut)
    private Button but;
    private TextView ontv;

    @Override
 

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ontv = (TextView) findViewById(R.id.ontv);

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


    public void onButton(View v){
        Intent intent = new
 
 Intent(MainActivity.this, SecondActivity.class);
        startActivity(intent);

    }

    //特別重要  @Subscribe(threadMode = ThreadMode.MAIN)
    @Subscribe(threadMode = ThreadMode.MAIN)
    public void onEventThread(FirstEvent event){
        String msg = "onEventThread已經收到了訊息"+event.getmEvent();
        ontv.setText(msg);
        Toast.makeText(this
 
,msg,Toast.LENGTH_SHORT).show();
    }

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

• 1.2、SecondeActivity第二個頁面

public class SecondActivity extends Activity {
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.second);

    }
    public void onPlay(View v){
        EventBus.getDefault().post(new FirstEvent("FirstEvent btn clicked222"));
    }

}

1.3、FirstEvent的一個方法

public class FirstEvent {
    private String mEvent;

    public String getmEvent() {
        return mEvent;
    }

    public void setmEvent(String mEvent) {
        this.mEvent = mEvent;
    }

    public FirstEvent(String mEvent){
        this.mEvent = mEvent;
    }
}