Android消息机制

核心提示：(2)当然需要一个Looper对象，来管理该MessageQueue，Android消息机制(4)，(3)我们可以构造Handler对象来push新消息到Message Queue里;或者接收Looper(从Message Queue取出)所送来的消息，(4)线程A的Handler对象可以传递给别的线程，让别的线程B或

(2)当然需要一个Looper对象，来管理该MessageQueue。

(3)我们可以构造Handler对象来push新消息到Message Queue里;或者接收Looper(从Message Queue取出)所送来的消息。

(4)线程A的Handler对象可以传递给别的线程，让别的线程B或C等能送讯息来给线程A(存于A的Message Queue里)。

(5)线程A的Message Queue里的消息，只有线程A所属的对象可以处理。

子线程传递消息给主线程

public class Activity2 extends Activity implements OnClickListener{

Button button = null;

TextView text = null;

MyHandler mHandler = null;

Thread thread ;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity1);

button = (Button)findViewById(R.id.btn);

button.setOnClickListener(this);

text = (TextView)findViewById(R.id.content);

}

public void onClick(View v) {

switch (v.getId()) {

case R.id.btn:

thread = new MyThread();

thread.start();

break;

}

}

private class MyHandler extends Handler{

public MyHandler(Looper looper){

super(looper);

}

@Override

public void handleMessage(Message msg) {//处理消息

text.setText(msg.obj.toString());

}

}

private class MyThread extends Thread{

@Override

public void run() {

Looper curLooper = Looper.myLooper();

Looper mainLooper = Looper.getMainLooper();

String msg ;

if(curLooper==null){

mHandler = new MyHandler(mainLooper);

msg = "curLooper is null";

}else{

mHandler = new MyHandler(curLooper);

msg = "This is curLooper";

}

mHandler.removeMessages(0);