Failed assertion: line 31 pos 16: 'dotsCount != null && dotsCount > 0': is not true

[NTMS2017]

Hi,

I am getting error as:
'package:dots_indicator/src/dots_indicator.dart': Failed assertion: line 31 pos 16: 'dotsCount != null && dotsCount > 0': is not true.

In init state part I am getting a data from remote server. Once the data verify I set the loadIndicator true so I can show the page. in area that data verify before setting the page loadIndicator to true in setState I set the pageLength. pageLength is integer and it totals of list of the data that I get from database. Everything works. Even I set the dotsCount = pageLength;

Any idea why I am keep getting this error?

My code:

return Scaffold(
    body: new Form(
      key: _formKey,
      child: Stack(
        children: [
          Column(
            children: [
              // IMAGE AREA TOP
              Container(
                height: 230.0,
                width: MediaQuery.of(context).size.width - 50.0,
                child: PageView.builder(
                  scrollDirection: Axis.horizontal,
                  controller: _pageController,
                  onPageChanged: ((_page) {
                    setState(() {
                      int _currentValue = int.parse('$_page');
                      currentIndexPage = _currentValue;
                    });
                  }),
                  itemCount: pageLength,
                  itemBuilder: (context, index) => _creditCard(context, currentIndexPage),
                ),
              ),
              // DOTS INDICTOR AREA
              Padding(
                padding: const EdgeInsets.only(top: 16.0),
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: [
                    DotsIndicator(
                      dotsCount: pageLength,
                      position: double.parse('$currentIndexPage'),
                      decorator: DotsDecorator(
                        color: Colors.black38,
                        activeColor: Colors.red,
                        size: const Size.square(9.0),
                        activeSize: const Size(18.0, 9.0),
                        activeShape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(5.0)),
                      ),
                    )
                  ],
                ),
              ),

flutter doctor -v:

[✓] Flutter (Channel stable, 1.22.6, on macOS 11.2.2 20D80 darwin-x64, locale en-GB)
    • Flutter version 1.22.6 at /Users/*********/flutter
    • Framework revision 9b2d32b605 (6 weeks ago), 2021-01-22 14:36:39 -0800
    • Engine revision 2f0af37152
    • Dart version 2.10.5

[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.3)
    • Android SDK at /Users/*********/Library/Android/sdk
    • Platform android-30, build-tools 30.0.3
    • ANDROID_HOME = /Users/*********/Library/Android/sdk
    • Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6915495)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 12.4)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 12.4, Build version 12D4e
    • CocoaPods version 1.10.1

[✓] Android Studio (version 4.1)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin installed
    • Dart plugin version 201.9335
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6915495)

[✓] IntelliJ IDEA Community Edition (version 2020.3.2)
    • IntelliJ at /Applications/IntelliJ IDEA CE.app
    • Flutter plugin installed
    • Dart plugin version 203.6912

[✓] Connected device (1 available)
    • iPhone 11 (mobile) • 92E3**************************************E72 • ios • com.apple.CoreSimulator.SimRuntime.iOS-14-4 (simulator)

[prakashsrv]

Getting the same issue. Got any solution?

[tuansonhq]

dotsCount: popularProducts.popularProductList.length <= 0 ? 1 : popularProducts.popularProductList.length

[Pyozer]

Hi, the error indicate that you have not set the param dotsCount with a positive value (>= 1). So dotsCount is maybe null or set as 0 or something else.

It's weird, your code seems to be "correct" to avoid having a 0 value, can you provide more code ?

[altoon-dev]

how did u solve this problem? now i've the same issue

[IashuraI]

2 Questions

1. Do you check for pages less then 0 or null before showing idicator?
2. Why do you parse double into position param?