How do I put a ListView under a scaffold with padding?

Question

I am quite new to flutter and I've been trying to set up a profile page for my app but it seems like I don't quite understand how these flutter widgets come together, I apologize if my question is quite dumb but I've been googling and failing at getting this to work. So basically I have a scaffold which holds a container thats supposed to display profile info (email, name, etc.), under it I'd like to place a listview, but flutter has been boggling my mind, I can't seem to understand how layouts work together, here is my code. When I try to do buildPage(), I get an error that the scaffold has infinite size, using buildBox() alone works. I'm not sure how to go about this. Any Help is appreciated

    import 'package:flutter/material.dart';

    class ProfileBox extends StatefulWidget {
      final String userEmail;
      const ProfileBox(this.userEmail);

      @override
      _ProfileBoxState createState() => _ProfileBoxState();
    }

    class _ProfileBoxState extends State<ProfileBox> {


      @override
      Widget build(BuildContext context) {
       return _buildPage();
      }



      Widget _buildBox(){
     return Scaffold(
          body: Align(
            alignment: Alignment.topCenter,
            child: LayoutBuilder(
              builder: (BuildContext context, BoxConstraints constraints) {
                return Container(
                      margin: const EdgeInsets.only(top: 20.0),
                      decoration: BoxDecoration(
                      color: Color(0xFF8185E2), border: Border.all(
                      color: Color(0xFF8185E2),
                      ),
                      borderRadius: BorderRadius.all(Radius.circular(20))
                      ),
                  height: constraints.maxHeight / 2.5,
                  width: MediaQuery.of(context).size.width -  (MediaQuery.of(context).size.width * 5)/100,
                   child: Center(
            child: Text(
             widget.userEmail,
              textAlign: TextAlign.center,
            ),
          ),
                );
              },
            ),
          ),
        );
      }


      Widget _buildPage()
      {
        return Column(children: <Widget>[
          _buildBox(),
          _buildList(),

        ],);

      }

      Widget _buildList()
      {
         return ListView(
            children: <Widget>[
              ListTile(
                title: Text('Sun'),
              ),
              ListTile(
                title: Text('Moon'),
              ),
              ListTile(
                title: Text('Star'),
              ),
            ],
          );
      }

}

Answer 1

Scaffold Widget should be a top Widget that contains the Column widget and all children Widget. I think you can start learning how to layout Widget in Flutter in order to understand more the way how Widget works, and the good place can be:https://flutter.dev/docs/development/ui/layout#lay-out-a-widget

Coming back to your question, you can just fix a bit to make it work:

class _ProfileBoxState extends State<ProfileBox> {
  @override
  Widget build(BuildContext context) {
    return _buildPage();
  }

  Widget _buildBox() {
    return Align(
      alignment: Alignment.topCenter,
      child: LayoutBuilder(
        builder: (BuildContext context, BoxConstraints constraints) {
          return Container(
            margin: const EdgeInsets.only(top: 20.0),
            decoration: BoxDecoration(
                color: Color(0xFF8185E2),
                border: Border.all(
                  color: Color(0xFF8185E2),
                ),
                borderRadius: BorderRadius.all(Radius.circular(20))),
            height: constraints.maxHeight / 2.5,
            width: MediaQuery.of(context).size.width -
                (MediaQuery.of(context).size.width * 5) / 100,
            child: Center(
              child: Text(
                widget.userEmail,
                textAlign: TextAlign.center,
              ),
            ),
          );
        },
      ),
    );
  }

  Widget _buildPage() {
    return Scaffold(
      body: Column(
        children: <Widget>[
          _buildBox(),
          _buildList(),
        ],
      ),
    );
  }

  Widget _buildList() {
    return ListView(
      children: <Widget>[
        ListTile(
          title: Text('Sun'),
        ),
        ListTile(
          title: Text('Moon'),
        ),
        ListTile(
          title: Text('Star'),
        ),
      ],
    );
  }
}

Answer 2

I just modified your code with Scaffold put the top Widget before the SafeArea , Please check the below code of it.

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';

class HomeScreen extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    // TODO: implement createState
    return _HomeScreen();
  }
}

class _HomeScreen extends State<HomeScreen> {
  @override
  Widget build(BuildContext context) {
    return _buildPage();
  }

  Widget _buildPage() {
    return SafeArea(
      top: true,
      child: Scaffold(
        body: Column(
          mainAxisAlignment: MainAxisAlignment.start,
          children: <Widget>[
            Container(
              margin: const EdgeInsets.only(top: 20.0),
              decoration: BoxDecoration(
                  color: Color(0xFF8185E2),
                  border: Border.all(
                    color: Color(0xFF8185E2),
                  ),
                  borderRadius: BorderRadius.all(Radius.circular(20))),
              height: MediaQuery.of(context).size.height / 2.5,
              width: MediaQuery.of(context).size.width -
                  (MediaQuery.of(context).size.width * 5) / 100,
              child: Center(
                child: Text(
                  "YOUR_EMAIL",
                  textAlign: TextAlign.center,
                ),
              ),
            ),
            Expanded(
              child: _buildList(),
            )
          ],
        ),
      ),
    );

    Column(
      children: <Widget>[
        //  _buildBox(),
        _buildList(),
      ],
    );
  }

  Widget _buildList() {
    return ListView(
      children: <Widget>[
        ListTile(
          title: Text('Sun'),
        ),
        ListTile(
          title: Text('Moon'),
        ),
        ListTile(
          title: Text('Star'),
        ),
      ],
    );
  }
}

And output of the program as follow