public class MyHandlerActivity extends Activity {
Button button;
MyHandler myHandler;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.handlertest);
button = (Button) findViewById(R.id.button);
myHandler = new MyHandler();
// 當創(chuàng)建一個新的Handler實例時, 它會綁定到當前線程和消息的隊列中,開始分發(fā)數據
// Handler有兩個作用, (1) : 定時執(zhí)行Message和Runnalbe 對象
// (2): 讓一個動作,在不同的線程中執(zhí)行.
// 它安排消息,用以下方法
// post(Runnable)
// postAtTime(Runnable,long)
// postDelayed(Runnable,long)
// sendEmptyMessage(int)
// sendMessage(Message);
// sendMessageAtTime(Message,long)
// sendMessageDelayed(Message,long)
// 以上方法以 post開頭的允許你處理Runnable對象
//sendMessage()允許你處理Message對象(Message里可以包含數據,)
MyThread m = new MyThread();
new Thread(m).start();
}
/**
* 接受消息,處理消息 ,此Handler會與當前主線程一塊運行
* */
class MyHandler extends Handler {
public MyHandler() {
}
public MyHandler(Looper L) {
super(L);
}
// 子類必須重寫此方法,接受數據
@Override
public void handleMessage(Message msg) {
// TODO Auto-generated method stub
Log.d("MyHandler", "handleMessage......");
super.handleMessage(msg);
// 此處可以更新UI
Bundle b = msg.getData();
String color = b.getString("color");
MyHandlerActivity.this.button.append(color);
}
}
class MyThread implements Runnable {
public void run() {
try {
Thread.sleep(10000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Log.d("thread.......", "mThread........");
Message msg = new Message();
Bundle b = new Bundle();// 存放數據
b.putString("color", "我的");
msg.setData(b);
MyHandlerActivity.this.myHandler.sendMessage(msg); // 向Handler發(fā)送消息,更新UI
}
}