EventBus跳转返回值（随机数）

主页面

package com.example.lx_eventbus;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import org.greenrobot.eventbus.EventBus;
import org.greenrobot.eventbus.Subscribe;
import org.greenrobot.eventbus.ThreadMode;

public class MainActivity extends AppCompatActivity {

    private Button btn;
    private TextView tv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //获取id
        btn = findViewById(R.id.button);
        tv = findViewById(R.id.tv_title);
        //注册EventBus
        EventBus eventBus = EventBus.getDefault();
        eventBus.register(this);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //跳转到第一个页面
                startActivity(new Intent(MainActivity.this,Main2Activity.class));

            }
        });
    }
    //注解：是给代码看的
    @Subscribe(threadMode = ThreadMode.MAIN)
    //接受数据
    public void Data(EventBus1 eventBus1){
        //赋值
        tv.setText(eventBus1.bus);
    }
    //停止
    @Override
    protected void onDestroy() {
        super.onDestroy();
        //解除注册
        EventBus.getDefault().unregister(this);//反注册EventBus
    }
}

布局

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.lx_eventbus.MainActivity">

    <Button
        android:id="@+id/button"
        android:text="跳转到发送页面的Activity"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"/>

    <TextView
        android:id="@+id/tv_title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/button"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="35dp"/>


</RelativeLayout>

第二个页面

package com.example.lx_eventbus;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import org.greenrobot.eventbus.EventBus;
import org.greenrobot.eventbus.Subscribe;
import org.greenrobot.eventbus.ThreadMode;

import java.util.Random;

public class Main2Activity extends AppCompatActivity {
    private Button send;
    private String uu;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        //获取id
        send = findViewById(R.id.send);
        Random random = new Random();
        uu = String.valueOf(random.nextInt());
        //点击事件
        send.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                EventBus.getDefault().post(new EventBus1(uu));
                finish();
            }
        });
    }
}

布局

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/activity_event_bus_send"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <Button
        android:id="@+id/send"
        android:text="向主页面使用EventBus发送一个事件"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>
</RelativeLayout>

工具类EventBus1

package com.example.lx_eventbus;

/**
 * data:2018/06/07.
 * author : 殷成龙(Administrator)
 * function :
 */

public class EventBus1 {
    public String bus;

    public EventBus1(String bus) {
        this.bus = bus;
    }
}

依赖

compile 'org.greenrobot:eventbus:3.0.0'