handle 与 Message

Posted 2020-06-21

 1 package com.douaty.asynctaskdemo;  
 2   
 3 import android.app.Activity;  
 4 import android.os.Bundle;  
 5 import android.os.Handler;  
 6 import android.os.Message;  
 7 import android.view.View;  
 8 import android.widget.Button;  
 9 import android.widget.TextView;  
10   
11   
12 public class MessageActivity extends Activity {  
13   
14     int messageId = 0x1000;  
15     TextView tv_connet;  
16     Button bt_send;  
17     Button bt_post;  
18   
19     private Handler handler = new Handler() {  
20         @Override  
21         public void handleMessage(Message msg){  
22             if (msg.what == messageId){  
23                 tv_connet.setText((String)msg.obj);  
24                 System.out.println("--arg1: " + msg.arg1 + ",  arg2: " + msg.arg2);  
25             }  
26         }  
27     };  
28   
29     @Override  
30     protected void onCreate(Bundle savedInstanceState) {  
31         super.onCreate(savedInstanceState);  
32         setContentView(R.layout.activity_message);  
33   
34         tv_connet = (TextView) findViewById(R.id.tv_showcontnet);  
35         bt_send = (Button) findViewById(R.id.bt_send);  
36         bt_post = (Button) findViewById(R.id.bt_post);  
37   
38         bt_send.setOnClickListener(new View.OnClickListener() {  
39             @Override  
40             public void onClick(View v) {  
41                 new Thread(new Mythread()).start();  
42             }  
43         });  
44   
45         bt_post.setOnClickListener(new View.OnClickListener() {  
46             @Override  
47             public void onClick(View v) {  
48                 handler.post(new Runnable() {  
49                     @Override  
50                     public void run() {  
51                         Message msg = Message.obtain(handler, messageId, 123, 456, "hello");  
52                         msg.sendToTarget();  
53                     }  
54                 });  
55             }  
56         });  
57     }  
58   
59     public class Mythread implements Runnable {  
60   
61         @Override  
62         public void run() {  
63             try {  
64                 Thread.sleep(1000);  
65             } catch (InterruptedException e) {  
66                 e.printStackTrace();  
67             }  
68 //            //方式1  
69 //            Message msg = Message.obtain();  
70 //            msg.obj = "我是一个Handler！";  
71 //            msg.what = messageId;  
72 //            handler.sendMessage(msg);  
73 //            //方式2  
74 //            Message msg = Message.obtain(handler);  
75 //            msg.obj = "我是一个Handler！";  
76 //            msg.what = messageId;  
77 //            msg.sendToTarget();  
78 //            //方式3  
79 //            Message msg = Message.obtain(handler, messageId);  
80 //            msg.obj = "我是一个Handler！";  
81 //            msg.sendToTarget();  
82 //            //方式4  
83 //            Message msg = Message.obtain(handler, messageId, "我是一个Handler！");  
84 //            msg.sendToTarget();  
85             //方式5  
86             Message msg = Message.obtain(handler, messageId, 123, 456, "hello");  
87             msg.sendToTarget();  
88         }  
89     }  
90 }