eventBus黏性事件的应用

如果所要完成的需求是要获取最新的数据并进行传递，我们可以考虑使用EventBus粘性事件

效果：在子页面的事件被触发时，接收消息  主页面只管跳转和发送消息

 ---------------------代码-----------------------------------

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private Button btn;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
       //初始化控件
        initView();


    }

    private void initView() {
        btn = (Button) findViewById(R.id.btn);

        btn.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn:
                //发送消息
                EventBus.getDefault().postSticky(new EventBusMessage("主页面发送的黏性事件"));
                Intent intent=new Intent(this,Main2Activity.class);
                  startActivity(intent);

                break;
        }
    }
}

---------------------------main2--------------------------------------
  

public class Main2Activity extends AppCompatActivity implements View.OnClickListener {

    private Button receive;
    private TextView tv_text;
     public  boolean flag=true;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
       //初始化控件
        initView();

    }

    private void initView() {
        receive = (Button) findViewById(R.id.receive);
        tv_text = (TextView) findViewById(R.id.tv_text);

        receive.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.receive:
                if(flag){
                    //注册
                    EventBus.getDefault().register(this);
                    flag=false;
                }
                break;
        }
    }
    //接收黏性事件,多了一个属性Sticky,改为true方是启动黏性事件
    @Subscribe(threadMode = ThreadMode.MAIN,sticky = true)
      public  void getMessage(EventBusMessage eventBusMessage){
         tv_text.setText(eventBusMessage.message);
      }




    //解除注册
    @Override
    protected void onDestroy() {
        super.onDestroy();
        EventBus.getDefault().unregister(this);
        //移除所有的黏性事件
        EventBus.getDefault().removeAllStickyEvents();
    }
}

------------------------------------------------------------

public class EventBusMessage {
    public String message;

    public EventBusMessage(String message) {
        this.message = message;
    }
}