EventBus.builder().executorService(Executors.newFixedTheadPool(NUM_THREADS)).installDefaultEventBus();

apply plugin: 'com.android.application'

android {
  compileSdkVersion 24
  buildToolsversion "24.0.3"

  defaultConfig {
    applicationId "com.eventbus.app"
    minSdkVersion 14
    targetSdkVersion 24
    versionCode 1
    versionName "1.0"

  }
  buildTypes {
    release {
      minifyEnabled false
      proguardFiles getDefaultProguardFile('proguard-android.txt'),'proguard-rules.pro'
    }
  }
}

dependencies {
  compile filetree(dir: 'libs',include: ['*.jar'])
  compile 'com.android.support:appcompat-v7:24.2.1'

  compile 'org.greenrobot:eventbus:3.0.0'
}

package com.eventbus.app;

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

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

public class MainActivity extends AppCompatActivity {

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

    //注册
    EventBus.getDefault().register( this );


    findViewById( R.id.button).setonClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        EventBus.getDefault().post( "我发射了");
      }
    });
  }

  /**
   * 自定义一个方法 hello() ，用来接收事件。
   * 方法名字可以随便写
   * @return
   */

  @Subscribe(threadMode = ThreadMode.MAIN)
  public void hello ( String event){
    /* Do something */
    Toast.makeText( this,event,Toast.LENGTH_SHORT).show();
  };


  @Override
  protected void onDestroy() {
    super.onDestroy();

    //取消注册,防止Activity内存泄漏
    EventBus.getDefault().unregister( this );
  }
}

@Subscribe(threadMode = ThreadMode.POSTING)
  public void onMessageEventPostThread(String event) {
    Log.e( "event PostThread","消息： " + event + " thread: " + Thread.currentThread().getName() );
  }

  @Subscribe(threadMode = ThreadMode.MAIN)
  public void onMessageEventMainThread(String event) {
    Log.e( "event MainThread","消息： " + event + " thread: " + Thread.currentThread().getName());
  }

  @Subscribe(threadMode = ThreadMode.BACKGROUND)
  public void onMessageEventBackgroundThread(String event) {
    Log.e( "event BackgroundThread","消息： " + event + " thread: " + Thread.currentThread().getName());
  }

  @Subscribe(threadMode = ThreadMode.ASYNC)
  public void onMessageEventAsync(String event) {
    Log.e( "event Async","消息： " + event + " thread: " + Thread.currentThread().getName());
  }

package com.eventbus.app;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;

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

public class MainActivity extends AppCompatActivity {

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

    //注册
    EventBus.getDefault().register( this );

    findViewById( R.id.button).setonClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        new Thread(new Runnable() {
          @Override
          public void run() {
            Log.d( "event 发射数据线程 : ",Thread.currentThread().getName() ) ;
            EventBus.getDefault().post( "我发射了");
          }
        }).start() ;
      }
    });
  }


  @Subscribe(threadMode = ThreadMode.POSTING)
  public void onMessageEventPostThread(String event) {
    Log.e( "event PostThread","消息： " + event + " thread: " + Thread.currentThread().getName());
  }


  @Override
  protected void onDestroy() {
    super.onDestroy();

    //取消注册,防止Activity内存泄漏
    EventBus.getDefault().unregister( this );
  }
}

package com.eventbus.app;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;

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

public class MainActivity extends AppCompatActivity {

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

    //注册
    EventBus.getDefault().register( this );

    findViewById( R.id.button).setonClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        Log.d( "event 发射数据线程 : ",Thread.currentThread().getName() ) ;
        EventBus.getDefault().post( "我发射了");
      }
    });
  }

  @Subscribe(threadMode = ThreadMode.POSTING)
  public void onMessageEventPostThread(String event) {
    Log.e( "event PostThread",防止Activity内存泄漏
    EventBus.getDefault().unregister( this );
  }
}

@Subscribe(threadMode = ThreadMode.MAIN,sticky = true )
public void onMessageEventMainThread(String event) {
Log.e( "event MainThread","消息： " + event + " thread: " + > Thread.currentThread().getName());
}

package com.eventbus.app;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;

import org.greenrobot.eventbus.EventBus;

public class MainActivity extends AppCompatActivity {

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

    findViewById( R.id.button).setonClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        Log.d( "event 发射数据线程 : ",Thread.currentThread().getName() ) ;
        EventBus.getDefault().postSticky( "我发射了");

        startActivity( new Intent( MainActivity.this,Activity2.class ));
      }
    });
  }
}

package com.eventbus.app;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;

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

public class Activity2 extends AppCompatActivity {

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_2);
    //注册
    EventBus.getDefault().register( this );
  }

  @Subscribe(threadMode = ThreadMode.MAIN,sticky = true )
  public void onMessageEventMainThread(String event) {
    Log.e( "event MainThread","消息： " + event + " thread: " + Thread.currentThread().getName());
  }

  @Override
  protected void onDestroy() {
    super.onDestroy();
    //取消注册,防止Activity内存泄漏
    EventBus.getDefault().unregister( this ) ;
  }
}

@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD})
public @interface Subscribe {
  ThreadMode threadMode() default ThreadMode.POSTING;

  /**
   * If true,delivers the most recent sticky event (posted with
   * {@link EventBus#postSticky(Object)}) to this subscriber (if event available).
   */
  boolean sticky() default false;

  /** Subscriber priority to influence the order of event delivery.
   * Within the same delivery thread ({@link ThreadMode}),higher priority subscribers will receive events before
   * others with a lower priority. The default priority is 0. Note: the priority does *NOT* affect the order of
   * delivery among subscribers with different {@link ThreadMode}s! */
  int priority() default 0;
}

static volatile EventBus defaultInstance;
 
  /** Convenience singleton for apps using a process-wide EventBus instance. */
  public static EventBus getDefault() {
    if (defaultInstance == null) {
      synchronized (EventBus.class) {
        if (defaultInstance == null) {
          defaultInstance = new EventBus();
        }
      }
    }
    return defaultInstance;
  }

public enum ThreadMode {

  /**
   * Subscriber will be called in the same thread,which is posting the event. This is the default. Event delivery
   * implies the least overhead because it avoids thread switching completely. Thus this is the recommended mode for
   * simple tasks that are kNown to complete is a very short time without requiring the main thread. Event handlers
   * using this mode must return quickly to avoid blocking the posting thread,which may be the main thread.
   */
   
  POSTING,/**
   * Subscriber will be called in Android's main thread (sometimes referred to as UI thread). If the posting thread is
   * the main thread,event handler methods will be called directly. Event handlers using this mode must return
   * quickly to avoid blocking the main thread.
   */
   
  MAIN,/**
   * Subscriber will be called in a background thread. If posting thread is not the main thread,event handler methods
   * will be called directly in the posting thread. If the posting thread is the main thread,EventBus uses a single
   * background thread,that will deliver all its events sequentially. Event handlers using this mode should try to
   * return quickly to avoid blocking the background thread.
   */
   
  BACKGROUND,/**
   * Event handler methods are called in a separate thread. This is always independent from the posting thread and the
   * main thread. Posting events never wait for event handler methods using this mode. Event handler methods should
   * use this mode if their execution might take some time,e.g. for network access. Avoid triggering a large number
   * of long running asynchronous handler methods at the same time to limit the number of concurrent threads. EventBus
   * uses a thread pool to efficiently reuse threads from completed asynchronous event handler notifications.
   */

  ASYNC
}