flutter textfield to accept only numbers code example

Example 1: flutter textfield number only

import 'package:flutter/services.dart';

keyboardType: TextInputType.number,
inputFormatters: [FilteringTextInputFormatter.digitsOnly],

Example 2: how to allow only characters and numbers in textfield flutter

inputFormatters: [new  WhitelistingTextInputFormatter(RegExp("[a-zA-Z0-9]")),],