EventBus

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:orientation="vertical"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.bw.eventbus.MainActivity">

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/btn"
        />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        android:id="@+id/text"
        />

</LinearLayout>

//需要jar包 EventBus2.4.jar

public class MainActivity extends AppCompatActivity {

    private Button mBtn;

    private TextView mText;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
        EventBus.getDefault().register(this);
        mBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent=new Intent(MainActivity.this,Main2Activity.class);
                startActivity(intent);
            }
        });
    }

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

        mText = (TextView) findViewById(R.id.text);
    }
//最常用的一个方法  名字不能自己定义必须是这个
    public void onEventMainThread(User message) {
        String string = message.getString();
        mText.setText(string);
    }
//关闭
    @Override
    protected void onDestroy() {
        super.onDestroy();
        EventBus.getDefault().unregister(this);
    }
}

public class Main2Activity extends AppCompatActivity  {

    /**
     * Button
     */
    private Button mButton;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        initView();
        mButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                EventBus.getDefault().post(new User("你嘞草原你嘞马，你想杂耍你杂耍"));
                finish();
            }
        });

    }

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

    }


}