14.Android-使用sendMessage线程之间通信

void handleMessage(Message msg);    //需要重写的方法,用来处理接收的消息,只有当接收到发送者发来的消息,才会回调该方法
Message obtainMessage();           //获取一个消息对象
boolean sendMessage(Message msg); //发送消息对象,发送成功的话,就会回调handleMessage()方法

package com.example.tcpdemo;

import java.io.IOException;
import java.net.Socket;
import java.net.UnknownHostException;

import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.app.Activity;
import android.view.Menu;

public class MainActivity extends Activity {

    MyThread mt;
    
    //定义一个handler
    public Handler mHandler = new Handler() {
        public void handleMessage(Message msg) {
            //打印发送者发来的消息
            System.out.println("main what:"+msg.what);
            System.out.println("main obj:"+msg.obj.toString());
            System.out.println("main arg1:"+msg.arg1);
            
        };
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        mt = new MyThread();
        mt.setHandler(mHandler);    //设置handler
        mt.start();    //启动线程
        
       
    }
}

package com.example.tcpdemo;


import android.os.Handler;
import android.os.Message;

public class MyThread extends Thread {
    
        
        public Handler mHandler=null;
        
        //获取另一个线程的Handler
        public void setHandler( Handler handler){
            mHandler = handler;
        }
        
        public void run(){
           
             try { //让线程睡眠3s。
                    Thread.sleep(3000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
             
             Message msg = mHandler.obtainMessage(); 
             //设置发送的内容
             msg.arg1 = 1;  
             msg.what = 3;  
             msg.obj = "this is MyThread"; 
             mHandler.sendMessage(msg);  
        }
}