只需用ListView替换Row。
还对高度/宽度进行了一些更改，将其签出。
import 'package:flutter/material.dart';void main() => runApp( new MaterialApp( home: new ResponsavelProfilePage(), ), );class ResponsavelProfilePage extends StatefulWidget { @override _ResponsavelProfilePageState createState() => new _ResponsavelProfilePageState();}class _ResponsavelProfilePageState extends State<ResponsavelProfilePage> { int _count = 1; @override Widget build(BuildContext context) { List<Widget> _contatos = new List.generate(_count, (int i) => new ContactRow()); return new Scaffold( appBar: new AppBar( title: new Text("NonstopIO"), ), body: new LayoutBuilder(builder: (context, constraint) { final _maxHeight = constraint.biggest.height / 3; final _biggerFont = TextStyle(fontSize: _maxHeight / 6); return new Center( child: new Column( mainAxisAlignment: MainAxisAlignment.center, children: <Widget>[ new TextFormField( decoration: new InputDecoration( labelText: 'Nome', ), ), new Container( padding: new EdgeInsets.all(20.0), ), new TextFormField( decoration: new InputDecoration( labelText: 'Data de nascimento', ), ), new Container( padding: new EdgeInsets.all(20.0), ), new Container( height: 200.0, child: new ListView( children: _contatos, scrollDirection: Axis.horizontal, ), ), new FlatButton( onPressed: _addNewContactRow, child: new Icon(Icons.add), ), //new ContactRow() ], ), ); })); } void _addNewContactRow() { setState(() { _count = _count + 1; }); }}class ContactRow extends StatefulWidget { @override State<StatefulWidget> createState() => new _ContactRow();}class _ContactRow extends State<ContactRow> { @override Widget build(BuildContext context) { return new Container( width: 170.0, padding: new EdgeInsets.all(5.0), child: new Column(children: <Widget>[ new TextFormField( decoration: new InputDecoration( labelText: 'Contato', ), ), new Text("Tipo Contato: "), new DropdownButton( value: _currentContactType, items: _dropDownMenuItems, onChanged: changedDropDownItem, ), new Container( padding: new EdgeInsets.all(20.0), ), ])); } List _contactTypes = ["Phone (SMS)", "Phone (Whatsapp)", "Email"]; List<DropdownMenuItem<String>> _dropDownMenuItems; String _currentContactType; @override void initState() { _dropDownMenuItems = getDropDownMenuItems(); _currentContactType = null; super.initState(); } List<DropdownMenuItem<String>> getDropDownMenuItems() { List<DropdownMenuItem<String>> items = new List(); for (String city in _contactTypes) { items.add(new DropdownMenuItem(value: city, child: new Text(city))); } return items; } void changedDropDownItem(String selectedCity) { setState(() { _currentContactType = selectedCity; }); }}
