flutterで画面遷移から戻った際にソフトキーボードが起動してしまう

dart

1import 'package:flutter/material.dart';2 3void main() {4 runApp(MyApp());5}6 7class MyApp extends StatelessWidget {8 @override9 Widget build(BuildContext context) {10 return MaterialApp(11 title: 'Flutter Navigation Demo',12 theme: ThemeData(13 primarySwatch: Colors.blue,14 ),15 home: FirstScreen(),16 );17 }18}19 20class FirstScreen extends StatefulWidget {21 @override22 _FirstScreenState createState() => _FirstScreenState();23}24 25class _FirstScreenState extends State<FirstScreen> {26 final TextEditingController _textController = TextEditingController();27 28 @override29 void dispose() {30 _textController.dispose();31 super.dispose();32 }33 34 @override35 Widget build(BuildContext context) {36 return Scaffold(37 appBar: AppBar(38 title: Text('First Screen'),39 ),40 body: Padding(41 padding: const EdgeInsets.all(16.0),42 child: Column(43 mainAxisAlignment: MainAxisAlignment.center,44 children: [45 TextField(46 controller: _textController,47 decoration: const InputDecoration(48 labelText: 'Enter some text with gesture',49 border: OutlineInputBorder(),50 ),51 ),52 SizedBox(height: 20),53 ElevatedButton(54 child: Text('Go to Second Screen'),55 onPressed: () {56 FocusScope.of(context).unfocus(); 57 Navigator.push(58 context,59 MaterialPageRoute(builder: (context) => SecondScreen()),60 );61 },62 ),63 ],64 ),65 ),66 );67 }68}69 70class SecondScreen extends StatelessWidget {71 @override72 Widget build(BuildContext context) {73 return Scaffold(74 appBar: AppBar(75 title: Text('Second Screen'),76 ),77 body: Center(78 child: ElevatedButton(79 child: Text('Go back'),80 onPressed: () {81 Navigator.pop(context);82 },83 ),84 ),85 );86 }87}