Flutter - PageController " ScrollController not attached to any scroll views."-CodePudding

Is there a way to animate to a page using PageController after awaiting an async function without causing the exception below to be thrown?

Exception:

_AssertionError ('package:flutter/src/widgets/scroll_controller.dart': Failed assertion: line 107 pos 12: '_positions.isNotEmpty': ScrollController not attached to any scroll views.)

Example widget:


class ExampleWidget extends StatelessWidget {
  ExampleWidget({super.key});

  final pageController = PageController();
  @override
  Widget build(BuildContext context) {
    return Stack(
      children: [
        PageView(
          controller: pageController,
          physics: const NeverScrollableScrollPhysics(),
          children: [],
        ),
        InkWell(
          onTap: () async {
            await exampleFn();
            await Future.delayed(const Duration()); // to wait for UI to build
            pageController.animateToPage(
              1,
              duration: const Duration(milliseconds: 500),
              curve: Curves.easeInOut
            );
          },
        )
      ],
    );
  }
}

Awaiting with if (pageController.hasClients) causes the animation to not occur. What is the right way to do this?

CodePudding user response：

I think it's working fine, you have to add the children property in the PageView, You can checkout this example:

import 'package:flutter/material.dart';

class ExampleWidget extends StatelessWidget {
  ExampleWidget({super.key});

  final pageController = PageController();
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Stack(
        children: [
          PageView(
            controller: pageController,
            physics: const NeverScrollableScrollPhysics(),
            children: [
              Container(
                color: Colors.amber,
              ),
              Container(
                color: Colors.red,
              )
            ],
          ),
          InkWell(
            onTap: () async {
              // await exampleFn();
              await Future.delayed(
                  const Duration(seconds: 2)); // to wait for UI to build
              pageController.animateToPage(1,
                  duration: const Duration(milliseconds: 500),
                  curve: Curves.easeInOut);
            },
          )
        ],
      ),
    );
  }
}

Here I have delayed for 2 seconds and it works perfectly fine.