Styjun

I have a tabbed activity with 3 fragments. First fragment allows user to select a test, Third fragment has a timer and a text view and some buttons. Second fragment has nothing in it as of now.

Inside fragment 3 I have a button that starts a timer, once the timer is started the textview refreshes every minute showing the time elapsed. Everything works well till this point.

Problem: Once the timer is started if I select fragment 1 and return back to fragment 3, the timer stops updating the textView. I know that the timer_elapsed is running correctly only textview is not updating.

I have tried FragmentActivity.RunOnUiThread(() => ); this works fine till the fragments are switched.

I did try using Loopers.MainLooper to update the screen and the problem still remained the same.

// update the screen every minute
 if (mActivity != null)
 
 mActivity.RunOnUiThread(() =>
 

 // set the progress bar
 progressBar.Progress = i32ProgressBarValue;
 textViewPercentage.Text = i32ProgressBarValue + "%";

 // set the text view
 textViewTestTime.Text = $"Globals.i32Days" + "D :" + $"Globals.i32Hours" + "H :" + $"Globals.i32Mins" + "M";
 );
 

I would like the textView to continue updating correctly when the fragments are switched and returned back to fragment 3

i wirte a sample use Timer in a TabbedActivity(use BottomNavigationView) which alse has three Fragments,in the third fragment,i use button to start the Timer for update button's text every two seconds, it works well (also works when switch fragments),below is the code in third fragment,you could refer to it:

Timer _dispatcherTimer;
TimerCallback timerDelegate;

public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
 
 // Use this to return your custom view for this Fragment
 // return inflater.Inflate(Resource.Layout.YourFragment, container, false);
 View view = inflater.Inflate(Resource.Layout.fragment_account, container, false);
 init(view);
 timerDelegate = new TimerCallback(Tick);

 return view;
 
 private void init(View view)
 
 button = view.FindViewById<Button>(Resource.Id.mybutton);
 button.Click += delegate
 
 _dispatcherTimer = new System.Threading.Timer(timerDelegate, null, 0, 2000);
 ;
 
 private void Tick(object state)
 

 this.Activity.RunOnUiThread(() =>
 
 //do something
 Random reRandom = new Random();
 int s = reRandom.Next(1000);
 button.Text = s.ToString();
 );