Вы можете указать номер как keyboardType для TextField, используя:
keyboardType: TextInputType.number
Проверьте мой файл main.dart
import 'package:flutter/material.dart';
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
// TODO: implement build
return new MaterialApp(
home: new HomePage(),
theme: new ThemeData(primarySwatch: Colors.blue),
);
}
}
class HomePage extends StatefulWidget {
@override
State<StatefulWidget> createState() {
return new HomePageState();
}
}
class HomePageState extends State<HomePage> {
@override
Widget build(BuildContext context) {
return new Scaffold(
backgroundColor: Colors.white,
body: new Container(
padding: const EdgeInsets.all(40.0),
child: new Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
new TextField(
decoration: new InputDecoration(labelText: "Enter your number"),
keyboardType: TextInputType.number,
inputFormatters: <TextInputFormatter>[
FilteringTextInputFormatter.digitsOnly
], // Only numbers can be entered
),
],
)),
);
}
}