Android线程间通信的Message机制

核心提示：Looper myLooper, mainLooper;myLooper = Looper.myLooper();mainLooper = Looper.getMainLooper(); //这是一个static函数String obj;if(myLooper == null){mNoLooperThreadHandl

Looper myLooper, mainLooper;

myLooper = Looper.myLooper();

mainLooper = Looper.getMainLooper(); //这是一个static函数

String obj;

if(myLooper == null){

mNoLooperThreadHandler = new EventHandler(mainLooper);

obj = "NoLooperThread has no looper and handleMessage function executed in main thread!";

}

else {

mNoLooperThreadHandler = new EventHandler(myLooper);

obj = "This is from NoLooperThread self and handleMessage function executed in NoLooperThread!";

}

mNoLooperThreadHandler.removeMessages(0);

if(false == postRunnable){

//send message to main thread

Message m = mNoLooperThreadHandler.obtainMessage(2, 1, 1, obj);

mNoLooperThreadHandler.sendMessage(m);

Log.e(sTag, "NoLooperThread id:" + this.getId());

}else{

//下面new出来的实现了Runnable接口的对象中run函数是在Main Thread中执行，不是在NoLooperThread中执行

//注意Runnable是一个接口，它里面的run函数被执行时不会再新建一个线程

//您可以在run上加断点然后在eclipse调试中看它在哪个线程中执行

mNoLooperThreadHandler.post(new Runnable(){

@Override

public void run() {

tv.setText("update UI through handler post runnalbe mechanism!");

noLooerThread.stop();

}

});

}

}

}

//OwnLooperThread has his own message queue by execute Looper.prepare();

class OwnLooperThread extends Thread{

private EventHandler mOwnLooperThreadHandler;

public void run() {

Looper.prepare();

Looper myLooper, mainLooper;

myLooper = Looper.myLooper();

mainLooper = Looper.getMainLooper(); //这是一个static函数

String obj;

if(myLooper == null){

mOwnLooperThreadHandler = new EventHandler(mainLooper);