I have been trying to stop a handler in my onPause(). Despite of calling removeCallbacks(timeRunnable) or removeCallbacksAndMessages(timeRunnable), the handler is not stopped. I have seen many answers here. But nothing worked. I might be missing something here.
Code:
public Runnable timeRunnable = new Runnable() {
#Override
public void run() {
Log.d("Here is my task");
timeHandler.postDelayed(timeRunnable, 5000);
}
};
public void startTimeHandler() {
timeHandler.post(timeRunnable);
}
public void stopTimeHandler() {
timeHandler.removeCallbacks(timeRunnable);
}
#Override
protected void onPause() {
super.onPause();
stopTimeHandler();
}
I am using below code snippet to run a thread every 10 seconds and update UI based on the values received from Server, stop thread on onPause.
Declare below variables in your class:
public class ActivityPortfolio extends AppCompatActivity {
Handler handler = new Handler();
Runnable runnable;
int delay = 10*1000;
//---------
In your onResume:
#Override
protected void onResume() {
handler.postDelayed(new Runnable(){
public void run(){
doSomething();
handler.postDelayed(this, delay);
}
}, delay);
super.onResume();
}
onPause():
#Override
protected void onPause() {
super.onPause();
handler.removeCallbacks(runnable); // this alone didnt work as we are calling postDelayed() in background as well.
handler.removeCallbacksAndMessages(null);//after adding this it stops thread
}
Related
I have Handler.I call my function every 10 second.Code working perfect,but i can't stop handler.This is my source code
handler=new Handler();
handler.post(runnable);
public Runnable runnable = new Runnable() {
#Override
public void run() {
myFunction(position);
handler.postDelayed(runnable,10000);
}
};
public void myFunction(int position)
{
if(position>10)
handler.removeCallbacks(runnable);
}
I can call myfunction every 10 second,but i can't stop handler.Ho i can solve my problem?
The problem is that myFunction removes the callback, then you still call handler.postDelayed to schedule a new one. There are plenty of ways to refactor this. For example:
handler=new Handler();
handler.post(runnable);
public Runnable runnable = new Runnable() {
#Override
public void run() {
boolean reschedule = myFunction(position);
if(reschedule) {
handler.postDelayed(runnable,10000);
}
}
};
public boolean myFunction(int position)
{
if(position>10) {
return false;
}
return true;
}
You don't have to remove callbacks on the handler because a new one will not be scheduled in the first place.
You remove callback in myFunction but you postDelayed again when myFunction returns, just invert lines inside run()
#Override
public void run() {
handler.postDelayed(runnable,10000);
myFunction(position);
}
I have a service. And there is a method called onServiceUpdate(). This method is similiar with onLocationChanged() in Google Maps API.
So i want to start CountDownTimer inside onServiceUpdate() method but showing error like this :
Can't create handler inside thread that has not called Looper.prepare()
java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
at android.os.Handler.<init>(Handler.java:200)
at android.os.Handler.<init>(Handler.java:114)
at android.os.CountDownTimer$1.<init>(CountDownTimer.java:114)
at android.os.CountDownTimer.<init>(CountDownTimer.java:114)
at skripsi.ubm.studenttracking.Service2$6.<init>(Service2.java:317)
at skripsi.ubm.studenttracking.Service2.onServiceUpdate(Service2.java:317)
This is my code :
#Override
public void onServiceUpdate(ServiceState state)
{
final float[] distance = new float[2];
Location.distanceBetween(state.getGeoPoint().getLatitude(), state.getGeoPoint().getLongitude(), 6.130607787619352,106.81839518499267, distance);
if (distance[0] > 25.0)
{
CountDownTimer cdt5 = new CountDownTimer(total_onServiceUpdate,1000) {
#Override
public void onTick(long millisUntilFinished) {
total_onServiceUpdate = millisUntilFinished/1000;
}
#Override
public void onFinish() {
sendSMS();
stopSelf();
}
}.start();
}
the onServiceUpdate() is an aysnchronous task that runs and notifies you, hence its a background thread. all you need to do is call timer.start(); from the main Thread, the Service actually runs on the main Thread, it is intentService that doesn't so, your solution is along the ways of
new Handler(Looper.getMainLooper()).post(new Runnable() {
#Override
public void run() {
CountDownTimer cdt5 = new CountDownTimer(total_onServiceUpdate,1000) {
#Override
public void onTick(long millisUntilFinished) {
total_onServiceUpdate = millisUntilFinished/1000;
}
#Override
public void onFinish() {
sendSMS();
stopSelf();
}
}.start();
}
});
now you can continue sir. Always call codes the flirt with the Screen on the main Looper
Hope it helps
Android :
Try This before calling a Handler
if (Looper.MyLooper() == null) { Looper.Prepare(); }
I think the problem is that in your sendSMS() you are trying to do something which requires UIThread (like updating a view).
Try this:
Handler mHandler = new Handler() {
public void handleMessage(Message msg){
sendSMS();
}};
Modify the onFinish method to
#Override
public void onFinish() {
mHandler.sendEmptyMessage(0);
stopSelf();
}
You cannot update a activity gui from a service via a handler because the handler has to be created in the gui thread.
instead you have to send a broadcast from your service and implement a local broadcast-receiver in the activity that gets this broadcast
I've got an activity with the following code:
Handler dataLoaderHandler = new Handler();
int mInterval = 3000;
public MyActivity myself;
Thread dataLoader = new Thread( new Runnable() {
#Override
public void run() {
Log.e("MyActivity","ReloadData");
new DataLoader(new JSONData(myself)).execute(Configuration.dataURL);
dataLoaderHandler.postDelayed(dataLoader, mInterval);
}
});
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
myself = this;
... some other stuff...
dataLoader.start();
}
... other code ...
#Override
protected void onDestroy() {
super.onDestroy();
Log.e("MyActivity","onDestroy ending thread");
try { dataLoader.join(); } catch(Exception e) { e.printStackTrace(); }
Log.e("MyActivity","onDestroy called");
}
When I hit the back button my activity gets destroyed but the thread still continues to run every 3 seconds. Why is the thread not stopped or better said deleted?
Because you haven't stopped it. Since calling stop() on a thread is already deprecated, you should stop the thread within the thread itself. This can be easily done by calling return on it.
However, don't expect your Thread to finish immediately you hit your back button. The Thread will probably run up until Android OS determines it has to (basically, it may take a while to stop even you call it).
You may want to check that question I made a time ago, it's well answered.
try:
boolean finished=false;
Handler dataLoaderHandler = new Handler();
int mInterval = 3000;
public MyActivity myself;
Thread dataLoader = new Thread( new Runnable() {
#Override
public void run() {
if(!finished){
Log.e("MyActivity","ReloadData");
new DataLoader(new JSONData(myself)).execute(Configuration.dataURL);
dataLoaderHandler.postDelayed(dataLoader, mInterval);}
}
});
#Override
protected void onStop() {
super.onStop();
finished=true;
}
How can i pause the handler.postDelayed() timer using a button. So when i click the same button again the handler.postDelayed() timer should resume.
handler.postDelayed(counterz, 60);
Handler does not have a timer to tweak. You are posting to event-queue of a thread, where a lot of other stuff is running as well.
You can cancel posted Runnable's:
handler.removeCallbacks(counterz);
And post again, to resume.
Handler does not have a pause method. You need to cancel and run again.
http://developer.android.com/reference/android/os/Handler.html#removeCallbacks(java.lang.Runnable)
public final void removeCallbacks (Runnable r)
Remove any pending posts of Runnable r that are in the message queue.
When not required you need to call m_handler.removeCallbacks(m_handlerTask) to cancel the run. If you need again you need to run the the task again.
Handler m_handler;
Runnable m_handlerTask ;
m_handler = new Handler();
m_handlerTask = new Runnable()
{
#Override
public void run() {
// do something
m_handler.postDelayed(m_handlerTask, 1000);
}
};
m_handlerTask.run(); // call run
Suppose you use a timer. Even timer does not have pause method.
public class YourActivity extends AppCompatActivity {
private static boolean handlerflag=false;
private Handler handler;
private Runnable runnable;
private int myind=0,index=0,count=0;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.your_activtiy);
//oncreate exe only
handlerflag=true;
handler = new Handler();
startyourtime(0);
}
private void startyourtime(int a) {
myind=0;
for (index=a; index<10 ;index++) {
myind++;
runnable=new Runnable() {
count++;
#Override
public void run() {
//your code here
}
};handler.postDelayed(runnable, Constants.TIME_LIMIT * myind);
}
#Override
protected void onPause() {
super.onPause();
handlerflag=false;
handler.removeCallbacksAndMessages(null);
}
#Override
protected void onResume() {
super.onResume();
if(!handlerflag)
{
startyourtime(count);
}
}
}
I want to reload my activity after every 1 minute. I tried using handler for this... but problem is that when i press back key of device, it doesn't stop and goes into an infinite loop..
here is my code what i have done--
public class Chat extends Activity {
Handler handler;
public void onCreate(Bundle savedInstance) {
super.onCreate(savedInstance);
setContentView(R.layout.chat);
handler = new Handler();
Toast.makeText(getApplicationContext(), "again", 400).show();
doTheAutoRefresh();
}
private void doTheAutoRefresh() {
handler.postDelayed(new Runnable() {
public void run() {
Intent intent = getIntent();
startActivity(intent);
finish();
//doTheAutoRefresh();
}
}, 10000);
}
public void onPause() {
super.onPause();
}
}
You should do this to remove all handler's messages and callbacks:
public void onPause() {
super.onPause();
handler.removeCallbacksAndMessages(null);
}