EventBus简单的实现

Posted 2020-08-09 王丰蛋哥

EventBus是最近项目用到的，也只是会些简单的功能，不过感觉功能蛮强大的。代码链接：http://download.csdn.net/detail/qq_29774291/9629346

EventBus是Guava的事件处理机制，是设计模式中的观察者模式（生产/消费者编程模型）的优雅实现。主要功能是替代Intent,Handler,BroadCast在Fragment，Activity，Service，线程之间传递消息.优点是开销小，代码更优雅。以及将发送者和接收者解耦。

一.下载的类库：https://github.com/greenrobot/EventBus

二.基本的使用：

　　1.在要接收消息的页面注册：

1 EventBus.getDefault().register(this);

　　2.在发送界面发送消息：

Student student = new Student(20, "张三", "男");
EventBus.getDefault().post(student);

　　3.在接受界面接受信息：

@Subscribe
    public void onMessageReviced(final Student Message) {
        //显示一个弹窗
        System.out.println("收到消息dddx ：" + Message);
        if(Message != null){
            showAlertDialog(this, "姓名：" + Message.getName() + "\\年龄：" + Message.getAge() + "\\性别：" +Message
                    .getSex());
        }
    }

　　4.解除注册：

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

主程序代码

 1 package com.item.jiejie.event;
 2 
 3 import de.greenrobot.event.EventBus;
 4 import de.greenrobot.event.Subscribe;
 5 import android.os.Bundle;
 6 import android.app.Activity;
 7 import android.app.AlertDialog;
 8 import android.content.Context;
 9 import android.content.DialogInterface;
10 import android.content.Intent;
11 import android.view.View;
12 import android.widget.Button;
13 import android.widget.TextView;
14 
15 public class MainActivity extends Activity {
16 
17     private TextView tv_View;
18     private Button btn_to_finish;
19 
20     @Override
21     protected void onCreate(Bundle savedInstanceState) {
22         super.onCreate(savedInstanceState);
23         setContentView(R.layout.activity_main);
24         setView();
25         EventBus.getDefault().register(this);
26     }
27     
28     @Override
29     protected void onDestroy() {
30         // TODO Auto-generated method stub
31         super.onDestroy();
32         EventBus.getDefault().unregister(this);
33     }
34     private void setView() {
35         // TODO Auto-generated method stub
36         tv_View = (TextView) findViewById(R.id.tv_text);
37         btn_to_finish = (Button) findViewById(R.id.btn_to_one);
38         btn_to_finish.setOnClickListener(new View.OnClickListener() {
39 
40             @Override
41             public void onClick(View arg0) {
42                 // TODO Auto-generated method stub
43                 startActivity(new Intent(MainActivity.this, OneActivity.class));
44             }
45         });
46     }
47     private boolean isShow = false;
48     @Override
49     protected void onStart() {
50         // TODO Auto-generated method stub
51         super.onStart();
52         isShow = true;
53     }
54     @Override
55     protected void onStop() {
56         // TODO Auto-generated method stub
57         super.onStop();
58         isShow =false;
59     }
60     @Subscribe
61     public void onMessageReviced(final String Message) {
62         tv_View.setText(Message);
63         System.out.println("收到消息ddd ：" + Message);
64     }
65 
66     @Subscribe
67     public void onMessageReviced(final Student Message) {
68         //显示一个弹窗
69         System.out.println("收到消息dddx ：" + Message);
70         if(Message != null){
71             showAlertDialog(this, "姓名：" + Message.getName() + "\\年龄：" + Message.getAge() + "\\性别：" +Message
72                     .getSex());
73         }
74     }
75     private void showAlertDialog(final Context context,String string){
76         AlertDialog.Builder dialog = new AlertDialog.Builder(context);
77         dialog.setTitle("我是标题");
78         dialog.setMessage(string);
79         dialog.setPositiveButton("确定", new DialogInterface.OnClickListener() {
80             
81             @Override
82             public void onClick(DialogInterface arg0, int arg1) {
83                 // TODO Auto-generated method stub
84                 
85             }
86         });
87         AlertDialog mDialog = dialog.create();
88         mDialog.show();
89     }
90 }