Android 消息处理机制——线程通信

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package com.example.hasee.androidmsg;import android.app.Activity;import android.os.Bundle;import android.view.Menu;import android.view.MenuItem;import android.os.Handler;import android.os.Looper;import android.os.Message;import android.os.Bundle;import android.view.Menu;import android.view.MenuItem;import android.widget.Button;import android.view.View;import android.util.Log;import android.os.HandlerThread;public class MainActivity extends Activity {    private Button mButton;    private Thread myThread;    private MyThread myThread2;    private HandlerThread myThread3;    private Handler mHandler;    private Handler mHandler3;    private final String TAG="MessageTest";    private int ButtonCount = 0;    private int mMessageCount = 0;    class MyRunnable implements Runnable {        /* 线程执行主体 */        public void run () {            int count = 0;            for (;;) {                ;            }        }    }    class MyThread extends Thread {        private Looper mLooper;        /* 发送消息者需要知道该线程的Looper */        public Looper getmLooper(){            if (!isAlive()) {                return null;            }            // If the thread has been started, wait until the looper has been created.            synchronized (this) {                while (isAlive() && mLooper == null) {                    try {                        wait();                    } catch (InterruptedException e) {                    }                }            }            return mLooper;        }        @Override        public void run() {            super.run();            Looper.prepare();//创建消息队列            synchronized (this) {                mLooper = Looper.myLooper();                notifyAll();            }            Looper.loop();//启动消息循环        }    }    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        mButton = (Button) findViewById(R.id.button);        mButton.setOnClickListener(new View.OnClickListener() {            public void onClick(View v) {                // Perform action on click                Message msg = new Message();                mHandler.sendMessage(msg);                mHandler3.post(new Runnable() {                    @Override                    public void run() {                        Log.d(TAG, "get Message for Thread3 ");                    }                });            }        });        /* 直接使用 Thread 无法实现消息处理，根本原因无法获取looper */        myThread = new Thread(new MyRunnable(), "MessageTestThread");        myThread.start();        /* 实现一个myThread类 */        myThread2 = new MyThread();        myThread2.start();        /* 通过Handler 来发送消息，发送给谁？Looper决定，同时传入回调函数，接收线程用于消息处理 */        mHandler = new Handler(myThread2.getmLooper(), new Handler.Callback() {            @Override            public boolean handleMessage(Message msg) {                Log.d(TAG, "myThread2 ");                return false;            }        });        /* 直接使用 HandlerThread 类 */        myThread3 = new HandlerThread("MessageTestThread3");        myThread3.start();        mHandler3 = new Handler(myThread3.getLooper());    }}
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