How do I join the thread to stop it?

Question

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    mProgressBar = (ProgressBar)findViewById(R.id.adprogress_progressBar);


    final Thread timerThread = new Thread() {

        private volatile boolean running = true;
        public void terminate() {
            running = false;
        }
        @Override
        public void run() {
            while(running) {
            mbActive = true;
                try {
                int waited = 0;
                    while(mbActive && (waited < TIMER_RUNTIME)) {
                    sleep(200);
                        if(mbActive) {
                            waited += 200;
                            updateProgress(waited);
                        }
                    }
                } catch(InterruptedException e) {
                running=false;
                }
            }
        }
    };
    timerThread.start();
}

public void onLocationChanged(Location location) {

    if (location != null) {

        TextView text;
        text = (TextView) findViewById(R.id.t2);
        String str= "Latitude is " + location.getLatitude() + "\nLongitude is " + location.getLongitude();

        text.setText(str);
        text.postInvalidate();
    }

}

How would I stop the thread in onCreate from onLocationChanged? I need to stop the progressbar once the GPS provides the coordinates. I need to join the threads using join(). Solution will be helpful.

Answer 1

使timerThread为类成员，而不是语言环境变量，通过这种方式，您应该从onLocationChanged方法访问它

Answer 2

改用AsyncTask，存储Future并自己停止线程。

Answer 3

If this is not a home work assignment, then I see no need to join() . Even more so when you're trying to join the UI thread with an arbitrary thread, effectively casuing an ANR .

Either:

1. Create you own class extending Thread , implement your terminate() method, and then call it whenever you want.

2. Create your own class extending AsyncTask , implementing LocationListener, and use its onProgressUpdate() method.

Answer 4

You can simply declare in your Activity a member :

private Thread mTimerThread = null;

then in your onCreate() replace :

final Thread timerThread = new Thread() {

with

mTimerThread = new Thread() {

and in onLocationChanged :

if (mTimerThread != null && mTimerThread.isAlive()) {
    mTimerThread.terminate();
}

to achieve what you want.

However, as others mentioned, I would also recommend using custom AsyncTask as it would be most clear way of threading in your case.