Android EventBus的使用

Android EventBus的使用

1.EventBus 2.x的使用请见:http://blog.csdn.net/harvic880925/article/details/40660137

2.EventBus 3.0的使用

今天在这里讨论原理，只介绍一下使用方法和一些特点，等会在后面附上一些链接地址(原理和下载链接)，亲们可以自己去看。

(1)订阅和取消订阅

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
EventBus.getDefault().register(this);//订阅
}

@Override
protected void onDestroy() {
super.onDestroy();
EventBus.getDefault().unregister(this);//解除订阅
}

(2)priority的作用

priority 值越大优先级越高，不设置时最低(比设置了的低)
相同的优先级或者都没设置优先级时谁先订阅谁先收到消息

package com.example.eventbus;

import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import de.greenrobot.event.Subscribe;
import de.greenrobot.event.ThreadMode;

/**
* 功能:用于测试不同优先级
* 特点:
* (1)priority 值越大优先级越高，不设置时最低(比设置了的低)
* (2)相同的优先级或者都没设置优先级时谁先订阅谁先收到消息
* */
public class SecondActivity extends BaseActivity {
private TextView textView;
private Button jump;

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

jump = (Button) findViewById(R.id.jump);
jump.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
start(ThirdActivity.class);
}
});
}

@Subscribe(threadMode = ThreadMode.MainThread)
public void onEvent(MsgEvent event){
Log.e("-->", "SecondActivity onEvent：priority = null, sticky = null, msg=" + event.msgData);
}

@Subscribe(threadMode = ThreadMode.MainThread, priority = 101)
public void onEventLowPriority(MsgEvent event){
Log.e("-->", "SecondActivity onEventLowPriority：priority = 101, sticky = null, msg=" + event.msgData);
}

@Subscribe(threadMode = ThreadMode.MainThread, priority = 101)
public void onEventLowPriority2(MsgEvent event){
Log.e("-->", "SecondActivity onEventLowPriority2：priority = 101, sticky = null, msg=" + event.msgData);
}

@Subscribe(threadMode = ThreadMode.MainThread, priority = 102)
public void onEventMidPriority(MsgEvent event){
Log.e("-->", "SecondActivity onEventMidPriority：priority = 102, sticky = null, msg=" + event.msgData);
}

@Subscribe(threadMode = ThreadMode.MainThread, priority = 102 , sticky = false)
public void onStickyEventMidPriority(MsgEvent event){
Log.e("-->", "SecondActivity onStickyEventMidPriority：priority = 102, sticky = false, msg=" + event.msgData);
}
}

打印结果:

08-25 16:04:30.755: E/-->(21838): SecondActivity onEventMidPriority：priority = 102, sticky = null, msg=send first msg
08-25 16:04:30.755: E/-->(21838): SecondActivity onStickyEventMidPriority：priority = 102, sticky = false, msg=send first msg
08-25 16:04:30.755: E/-->(21838): SecondActivity onEventLowPriority：priority = 101, sticky = null, msg=send first msg
08-25 16:04:30.755: E/-->(21838): SecondActivity onEventLowPriority2：priority = 101, sticky = null, msg=send first msg
08-25 16:04:30.755: E/-->(21838): SecondActivity onEvent：priority = null, sticky = null, msg=send first msg

(3)Sticky

后订阅时，sticky为true的处理函数才能才能收到消息
后订阅时，priority优先级貌似无效

package com.example.eventbus;

import de.greenrobot.event.EventBus;
import de.greenrobot.event.Subscribe;
import de.greenrobot.event.ThreadMode;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.ActionMode;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

/**
* 功能:用于测试事件发送后才订阅消息,sticky的作用
* 事件发送方法:EventBus.getDefault().postSticky()
* 描述:第一次显示该页面时不订阅，等postSticky消息发送后，再回到本页面时，在OnResume中订阅消息
* 特点:
* (1)后订阅时，sticky为true的处理函数才能才能收到消息
* (2)后订阅时，priority优先级貌似无效
* */
public class UnregisterActivity extends Activity{
private boolean firstResume = true;//是否是第一次Resume
private TextView textView;
private Button jump;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
firstResume = true;
jump = (Button) findViewById(R.id.jump);
jump.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent in = new Intent(UnregisterActivity.this, SecondActivity.class);
startActivity(in);
}
});
}

@Subscribe(threadMode = ThreadMode.MainThread)
public void onEvent(MsgEvent event) {
Log.e("-->", "UnregisterActivity onEvent：" + event.msgData);
}

@Subscribe(threadMode = ThreadMode.MainThread, sticky = true)
public void onStickyEvent(MsgEvent event) {
Log.e("-->", "UnregisterActivity onStickyEvent： priority = null, msg = " + event.msgData);
}

@Subscribe(threadMode = ThreadMode.MainThread, sticky = true, priority = 1010)
public void onStickyEvent2(MsgEvent event) {
Log.e("-->", "UnregisterActivity onStickyEvent2：priority = 1010, msg=" + event.msgData);
}

@Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
if(!firstResume){
EventBus.getDefault().register(this);
}
firstResume = false;
}

@Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
EventBus.getDefault().unregister(this);
}
}

消息发送后，返回到该页面时在OnResume中订阅消息，只有sticky=true的才能收到消息

这里附上我的demo下载地址:

EventBus 3.0相关参考链接:
http://www.cnblogs.com/whoislcj/p/5595714.html http://blog.csdn.net/angcyo/article/details/48166849