public class MainActivity extends AppCompatActivity {   private TextView tvMain;   private HandlerThread mHandlerThread;  //子線程中的handler  private Handler mThreadHandler;  //UI線程中的handler  private Handler mMainHandler = new Handler();   //以防退出界面后Handler還在執(zhí)行  private boolean isUpdateInfo;  //用以表示該handler的常熟  private static final int MSG_UPDATE_INFO = 0x110;   @Override  protected void onCreate(Bundle savedInstanceState)  {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);     tvMain = (TextView) findViewById(R.id.tv_main);     initThread();  }    private void initThread()  {    mHandlerThread = new HandlerThread("check-message-coming");    mHandlerThread.start();     mThreadHandler = new Handler(mHandlerThread.getLooper())    {      @Override      public void handleMessage(Message msg)      {        update();//模擬數(shù)據(jù)更新         if (isUpdateInfo)          mThreadHandler.sendEmptyMessage(MSG_UPDATE_INFO);      }    };   }   private void update()  {    try    {      //模擬耗時(shí)      Thread.sleep(2000);      mMainHandler.post(new Runnable()      {        @Override        public void run()        {          String result = "每隔2秒更新一下數(shù)據(jù)：";          result += Math.random();          tvMain.setText(result);        }      });     } catch (InterruptedException e)    {      e.printStackTrace();    }   }   @Override  protected void onResume()  {    super.onResume();    //開(kāi)始查詢    isUpdateInfo = true;    mThreadHandler.sendEmptyMessage(MSG_UPDATE_INFO);  }   @Override  protected void onPause()  {    super.onPause();    //停止查詢    //以防退出界面后Handler還在執(zhí)行    isUpdateInfo = false;    mThreadHandler.removeMessages(MSG_UPDATE_INFO);  }   @Override  protected void onDestroy()  {    super.onDestroy();    //釋放資源    mHandlerThread.quit();  }}

public class HandlerThread extends Thread {  int mPriority;  int mTid = -1;  Looper mLooper;   public HandlerThread(String name) {    super(name);    mPriority = Process.THREAD_PRIORITY_DEFAULT;  }    public HandlerThread(String name, int priority) {    super(name);    mPriority = priority;  }    protected void onLooperPrepared() {  }   @Override  public void run() {    mTid = Process.myTid();    Looper.prepare();    synchronized (this) {      mLooper = Looper.myLooper();      notifyAll();    }    Process.setThreadPriority(mPriority);    onLooperPrepared();    Looper.loop();    mTid = -1;  }    public Looper getLooper() {    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;  }    public boolean quit() {    Looper looper = getLooper();    if (looper != null) {      looper.quit();      return true;    }    return false;  }    public boolean quitSafely() {    Looper looper = getLooper();    if (looper != null) {      looper.quitSafely();      return true;    }    return false;  }    public int getThreadId() {    return mTid;  }}