Flutter中，没有固定高度的嵌套listview有溢出且不可滚动

Question

In my project, I have implemented a questionnaire format page.

One questionnaire has a many parts (1,2,3...) and each part has a many questions.

And, the questions have a many selects (Very bad, bad, so-so, good, Very good, etc.).

To implement this page, I chose a nested listview (inside listview, another listview is existed).

This is a sample code that has a same widget tree with mine.

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Column(
        mainAxisSize: MainAxisSize.min,
        mainAxisAlignment: MainAxisAlignment.start,
        children: [
          const Text('this is text inside 1st column. blue container'),
          Column(
            children: [
              const Text('this is text inside 2nd column. about part title'),
              ListView.separated(
                shrinkWrap: true,
                itemBuilder: (BuildContext firstListViewContext,
                    int firstListViewIndex) {
                  return Column(
                    children: [
                      const Text(
                          'this is text inside 1st listview and 3nd column. question title'),
                      ListView.separated(
                        shrinkWrap: true,
                        itemBuilder: (BuildContext context, int index) {
                          return Text(
                              'this is text inside 2nd listview and 3nd column, question selector list');
                        },
                        separatorBuilder: (BuildContext context, int index) =>
                            const SizedBox(height: 4),
                        itemCount: 20,
                      ),
                    ],
                  );
                },
                separatorBuilder: (BuildContext context, int index) =>
                    const SizedBox(height: 4),
                itemCount: 1,
              ),
            ],
          ),
          Spacer(),
          ElevatedButton(
              onPressed: () {},
              child: Text('this is button inside 1st column.')),
        ],
      ),
    );
  }
}

Above code has a overflow problem and the question listview cannot be scrolled...

Is there any way I can get rid of overflows in the code above and scroll down the problem list?

---

Edit 1.

In my code, only question's listview should be scrollable.

The button should be attached to the bottom of the screen.

Answer 1

Try this:

Column(
        mainAxisSize: MainAxisSize.min,
        mainAxisAlignment: MainAxisAlignment.start,
        children: [
          const Text('this is text inside 1st column. blue container'),
          Expanded(
            child: Column(
              children: [
                const Text('this is text inside 2nd column. about part title'),
                Expanded(
                  child: ListView.separated(
                    itemBuilder: (BuildContext firstListViewContext,
                        int firstListViewIndex) {
                      return Column(
                        children: [
                          const Text(
                              'this is text inside 1st listview and 3nd column. question title'),
                          ListView.separated(
                            shrinkWrap: true,
                            itemBuilder: (BuildContext context, int index) {
                              return Text(
                                  'this is text inside 2nd listview and 3nd column, question selector list');
                            },
                            separatorBuilder:
                                (BuildContext context, int index) =>
                                    const SizedBox(height: 4),
                            itemCount: 20,
                          ),
                        ],
                      );
                    },
                    separatorBuilder: (BuildContext context, int index) =>
                        const SizedBox(height: 4),
                    itemCount: 1,
                  ),
                ),
              ],
            ),
          ),
          Spacer(),
          ElevatedButton(
              onPressed: () {},
              child: Text('this is button inside 1st column.')),
        ],
      )