Android中的MessageHandler機制一

 

總體思想就是兩個（多個）線程共用一Block Storage地區，它們並發地操作這塊記憶體。

 

下面是我自己初步寫的類比程式，有需要程式者可以聯絡我QQ402320131哈~：

 

這裡僅貼上Hander, HandlerThread, Looper2

 

package com.zte.liu;

 

public class Handler {

 

 private Looper2 looper = null;

 

 public Handler(Looper2 looper){

  this.looper = looper;

 }

 

 public Message obtainMessage(){

  return new Message(this);

 }

 

 public Message obtainMessage(int id){

  return new Message(id, this);

 }

 

 public void dispatchMsg(Message msg){

  handleMessage(msg);

 }

 

 public Looper2 getLooper(){

  return looper;

 }

 

 public void handleMessage(Message msg){//鉤子函數

  System.out.println(msg.getId());

 }

}

 

 

 

 

public class HandlerThread implements Runnable{

 

 public void run(){

  Looper2.prepare();

  Looper2.loop();

 }

 

}

 

 

 

 

 

package com.zte.liu;

 

public class Looper2 {

 

 private static Looper2 looper = null;

 private MessageQueue<Message> mQueue;

 private Looper2(){

  mQueue = new MessageQueue();

 }

 

 public static void prepare(){

  if(looper == null){

   looper = new Looper2();

  } www.2cto.com

 }

 

 public static Looper2 myLooper(){

  prepare();

  return looper;

 }

 

 public MessageQueue<Message> getQueue(){

  return mQueue;

 }

 

 public static final void loop(){

  System.out.println("loop begin...");

  Looper2 looper = myLooper();

  MessageQueue<Message> queue = looper.mQueue;

  if(looper == null) {

   return;

  }

  while(true){

   System.out.println("----queue size ="+queue.size());

   try {

    Thread.sleep(1000);

   } catch (InterruptedException e) {

    e.printStackTrace();

   }

   Message msg = (Message)queue.next();

   if(msg != null){

    if(msg.getHandler() == null)return;

    else{

     msg.getHandler().dispatchMsg(msg);

     Message.recycle(msg);

    }

   }

  }

 }

}

摘自：liuyangsyouxiang的專欄