Flutter: Exception using Navigator.of(context).pop();

Question

Every time I use Navigator.of(context).pop(); to return to the previous view I always get the

Unhandled Exception: NoSuchMethodError: The method 'call' was called on null.

message.

However, the app successfully goes back to the previous view, but I don't know why I always get this message that sometimes causes a crash. What could it be?

#0      _rootRunUnary (dart:async/zone.dart:1198:47)
#1      _CustomZone.runUnary (dart:async/zone.dart:1100:19)
#2      _FutureListener.handleValue (dart:async/future_impl.dart:143:18)
#3      Future._propagateToListeners.handleValueCallback (dart:async/future_impl.dart:696:45)
#4      Future._propagateToListeners (dart:async/future_impl.dart:725:32)
#5      Future._completeWithValue (dart:async/future_impl.dart:529:5)
#6      Future._asyncCompleteWithValue. (dart:async/future_impl.dart:567:7)
#7      _rootRun (dart:async/zone.dart:1190:13)
#8      _CustomZone.run (dart:async/zone.dart:1093:19)
#9      _CustomZone.runGuarded (dart:async/zone.dart:997:7)
#10     _CustomZone.bindCallbackGuarded. (dart:async/zone.dart:1037:23)
#11     _microtaskLoop (dart:async/schedule_microtask.dart:41:21)
#12     _startMicrotaskLoop<…>

I usually use an Inkwell associated with an icon to call the method. In example:

InkWell(onTap: () => Navigator.of(context).pop(), 

  child: Icon(Icons.chevron_left_rounded, color: Constants.COLOR_DEF, size: 30));

user_8319940 · Answer

Nevermind, found the problem.

Basically, when going from one page to another, I've always called "Navigator.of(context).push(new MaterialPageRoute)" passing also a callback function (if necessary). When that callback function is not passed (null) the error is thrown.

Thanks anyway to anyone who replied!

user_11847989 · Answer

this error usually arrives when the Navigator.of(context).currentState is null

which means you don't have any Route below current route, so you can't pop the route. Check this do you have any route below this route or not??

Flutter: Exception using Navigator.of(context).pop();

2 Answers