Programming Mobile Application Development : Flutter fundamental Day 2

Byadmin

Jan 6, 2026

เปิด Android Studio กดปุ่ม new project (กรณีหาปุ่มไม่เจอให้กลับมาหน้าแรก โดยเลือก menu file แล้ว close project ก่อน)
เมื่อสร้าง app flutter แล้วให้ลองกดแสดงผล
ลองแก้ไข app bar
แก้ไขชื่อ title ใน app bar

ทดสอบแก้ไขโค้ดดังภาพ

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // TRY THIS: Try running your application with "flutter run". You'll see
        // the application has a purple toolbar. Then, without quitting the app,
        // try changing the seedColor in the colorScheme below to Colors.green
        // and then invoke "hot reload" (save your changes or press the "hot
        // reload" button in a Flutter-supported IDE, or press "r" if you used
        // the command line to start the app).
        //
        // Notice that the counter didn't reset back to zero; the application
        // state is not lost during the reload. To reset the state, use hot
        // restart instead.
        //
        // This works for code too, not just values: Most code changes can be
        // tested with just a hot reload.
        colorScheme: .fromSeed(seedColor: Colors.deepPurple),
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
      _counter++;//+1 +1
    });
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        //comment คือพิมพ์ สแลชสองอันติดกัน
        backgroundColor: Colors.amber[300],
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text('my app'),
      ),
      body: Center(

        child: Column(
          mainAxisAlignment: .center,
          children: [
            const Text('สมโภชน์'),
            Text(
              'กุลธารารมณ์',

            ),
          ],
        ),
      ),

    );
  }
}

ตัวอย่าง row และ column

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // TRY THIS: Try running your application with "flutter run". You'll see
        // the application has a purple toolbar. Then, without quitting the app,
        // try changing the seedColor in the colorScheme below to Colors.green
        // and then invoke "hot reload" (save your changes or press the "hot
        // reload" button in a Flutter-supported IDE, or press "r" if you used
        // the command line to start the app).
        //
        // Notice that the counter didn't reset back to zero; the application
        // state is not lost during the reload. To reset the state, use hot
        // restart instead.
        //
        // This works for code too, not just values: Most code changes can be
        // tested with just a hot reload.
        colorScheme: .fromSeed(seedColor: Colors.deepPurple),
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
      _counter++;//+1 +1
    });
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        //comment คือพิมพ์ สแลชสองอันติดกัน
        backgroundColor: Colors.amber[300],
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text('my app'),
      ),
      body: Center(

        child: Column(
          mainAxisAlignment: .center,
          children: [
           Row(
             children: [
               Text('สมโภชน์'),
               Text('  '),
               Text('กุลธารารมณ์'),
             ],
           ),
            Row(
              children: [
                Text('อริสา'),
                Text('  '),
                Text('บีบี'),
              ],
            )




          ],
        ),

      ),

    );
  }
}

การเอารูปจาก internet มาแสดงใน app ทำได้ดังนี้

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('ตัวอย่าง Layout'),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              Image.network('https://t3.gstatic.com/licensed-image?q=tbn:ANd9GcQrJzSTI4OI2aLe6DgXajqOO5E87Z3nGiTCZcn_-Q9xqZ_CLtLNLeYib4xxZUSGZgzb'),
              SizedBox(height: 10),
              Text(
                'โดนัลด์ ทรัมป์',
                style: TextStyle(fontSize: 50,color: Colors.blue),

              ),
            ],
          ),
        ),
      ),
    );
  }
}

การเอาภาพไว้ในแอพและเรียกใช้งาน
เริ่มจากไปสร้าง folder แล้วเอาไฟลภาพไปไว้ใน folder ที่สร้าง
ไปแก้ pubspec.yaml

สร้างปุ่ม home และ about us ใน app bar แล้วสร้าง page app bar ตามภาพ

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: HomePage(),
    );
  }
}

class HomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('ตัวอย่าง Layout'),
        actions: [
          IconButton(
            icon: Icon(Icons.home),
            onPressed: () {
              // อยู่ในหน้าเดิมแล้ว ไม่ต้องทำอะไร
            },
          ),
          IconButton(
            icon: Icon(Icons.info),
            onPressed: () {
              Navigator.push(
                context,
                MaterialPageRoute(builder: (context) => AboutPage()),
              );
            },
          ),
        ],
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Image.asset('assets/trump.png'),
            SizedBox(height: 20),
            Text(
              'ชื่อของคุณ',
              style: TextStyle(fontSize: 24),
            ),
          ],
        ),
      ),
    );
  }
}

class AboutPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('About Us'),
      ),
      body: Center(
        child: Text(
          'นี่คือหน้าข้อมูลเกี่ยวกับแอปของเรา',
          style: TextStyle(fontSize: 20),
        ),
      ),
    );
  }
}

ย้าย ปุ่มมาใน body

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: HomePage(),
    );
  }
}

class HomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                IconButton(
                  icon: Icon(Icons.home),
                  onPressed: () {
                    // อยู่ในหน้าเดิมแล้ว ไม่ต้องทำอะไร
                  },
                ),
                SizedBox(width: 20),
                IconButton(
                  icon: Icon(Icons.info),
                  onPressed: () {
                    Navigator.push(
                      context,
                      MaterialPageRoute(builder: (context) => AboutPage()),
                    );
                  },
                ),
              ],
            ),
            SizedBox(height: 20),
            Image.asset('assets/image.jpg'),
            SizedBox(height: 20),
            Text(
              'ชื่อของคุณ',
              style: TextStyle(fontSize: 24),
            ),
          ],
        ),
      ),
    );
  }
}

class AboutPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('About Us'),
      ),
      body: Center(
        child: Text(
          'นี่คือหน้าข้อมูลเกี่ยวกับแอปของเรา',
          style: TextStyle(fontSize: 20),
        ),
      ),
    );
  }
}