Im new to Flutter. I got this error Null check operator used on a null value error. but I could not solve it. This is the place where the second exception "The relevant error-causing widget was Consumer" occurs:

Future<void> _handleAnimation(BuildContext context) async {
    // add_remove shows the options;
    // remove_add hides the options;
    // back_remove pops the sub menu of the option selected

    AnimationProvider animationProvider =
        Provider.of<AnimationProvider>(context, listen: false);
    animationProvider.flareAnimationCompleted = false;
    ShowPageProvider showPageProvider =
        Provider.of<ShowPageProvider>(context, listen: false);
    print(animationProvider.animationController.isCompleted);
    if (!animationProvider.popPage) {
      if (animationProvider.animationController.isDismissed &&
          animationProvider.initializeProvider) {
        print("forward*****************)))))");
        animationProvider.flareAnimation = FlareStatus.add_remove;
        _animationController.forward();
        showPageProvider.animationStatus = AnimationStatus.forward;
      } else if (animationProvider.animationController.isCompleted ||
          !animationProvider.initializeProvider) {
        print("revrese*****************)))))");
        animationProvider.flareAnimation = FlareStatus.remove_add;

        _animationController.reverse();

        showPageProvider.animationStatus = AnimationStatus.reverse;
        animationProvider.setInitializeProviderValue = true;
      }
    } else {
      print("back*****************)))))");
      if (!animationProvider.initializeProvider) {
        _animationController.forward();
      }
      animationProvider.flareAnimation = FlareStatus.back_remove;
      await animationProvider.function();
      animationProvider.function = () {};
      Navigator.of(animationProvider.pageContext).pop();
      animationProvider.popPage = false;
    }
  }

this is the debugger output:

════════ Exception caught by widgets library ═══════════════════════════════════ Null check operator used on a null value The relevant error-causing widget was CustomBottomBar ════════════════════════════════════════════════════════════════════════════════

════════ Exception caught by widgets library ═══════════════════════════════════ Null check operator used on a null value The relevant error-causing widget was Consumer ════════════════════════════════════════════════════════════════════════════════

Please help me. Thank you

CodePudding user response：

You are getting this error because you are using a null check operator "!" on a variable that is already null. The solution is to properly initialize those variables or to avoid calling them when they're not initialized. Search for parts of code where you have added "!" operator and see if those variables are properly initialized or not. If you want more help, please edit your question to include the entire code where you're facing this error.

CodePudding user response：

you are getting this error because you are using the null check operator(!) on a null value. So get confirm your null check operator used variable is assign properly or not.

The Other Solution is you can initialize default value to the your variable

ex:-

int age=10; or you can use age ?? 20 instead of !age