[flutter] 미세먼지 앱_Hive_연습

1)

2) screen

/test_screen.dart

import 'package:dusty_dust/main.dart';
import 'package:dusty_dust/screen/test2_screen.dart';
import 'package:flutter/material.dart';
import 'package:hive_flutter/hive_flutter.dart';

class TestScreen extends StatefulWidget {
  const TestScreen({Key? key}) : super(key: key);

  @override
  State<TestScreen> createState() => _TestScreenState();
}

class _TestScreenState extends State<TestScreen> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('TestScreen'),
      ),
      body: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          ValueListenableBuilder<Box>(
            valueListenable: Hive.box(testBox).listenable(),
            builder: (context, box, widget) {
              return Column(
                children: box.values
                    .map(
                      (e) => Text(e.toString()),
                    )
                    .toList(),
              );
            },
          ),
          ElevatedButton(
            onPressed: () {
              final box = Hive.box(testBox);

              print('keys : ${box.keys.toList()}');
              print('values : ${box.values.toList()}');
            },
            child: Text(
              '박스 프린트하기!',
            ),
          ),
          ElevatedButton(
            onPressed: () {
              final box = Hive.box(testBox);

              box.add('테스트2');

              // 데이터를 생성하거나
              // 업데이트할 때
              box.put(100, '테스트4');
            },
            child: Text(
              '데이터 넣기!',
            ),
          ),
          ElevatedButton(
            onPressed: () {
              final box = Hive.box(testBox);

              // key값으로 가져오기
              print(box.get(100));

              // index 위치로 가져오기
              print(box.getAt(0));
            },
            child: Text(
              '특정값 가져오기!',
            ),
          ),
          ElevatedButton(
            onPressed: () {
              final box = Hive.box(testBox);

              box.deleteAt(2);
            },
            child: Text(
              '삭제하기!',
            ),
          ),
          ElevatedButton(
            onPressed: () {
              Navigator.of(context).push(
                MaterialPageRoute(
                  builder: (_) => Test2Screen(),
                ),
              );
            },
            child: Text(
              '화면전환',
            ),
          ),
        ],
      ),
    );
  }
}

/test2_screen,dart

import 'package:flutter/material.dart';
import 'package:hive_flutter/hive_flutter.dart';

import '../main.dart';

class Test2Screen extends StatefulWidget {
  const Test2Screen({Key? key}) : super(key: key);

  @override
  State<Test2Screen> createState() => _Test2ScreenState();
}

class _Test2ScreenState extends State<Test2Screen> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Test2Screen'),
      ),
      body: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          ValueListenableBuilder<Box>(
            valueListenable: Hive.box(testBox).listenable(),
            builder: (context, box, widget) {
              return Column(
                children: box.values
                    .map(
                      (e) => Text(e.toString()),
                )
                    .toList(),
              );
            },
          ),
        ],
      ),
    );
  }
}

3) main.dart

import 'package:dusty_dust/screen/home_screen.dart';
import 'package:dusty_dust/screen/test_screen.dart';
import 'package:flutter/material.dart';
import 'package:hive_flutter/hive_flutter.dart';

const testBox = 'test';

void main() async {
  await Hive.initFlutter();

  await Hive.openBox(testBox);

  runApp(
    MaterialApp(
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        fontFamily: 'sunflower',
      ),
      home: TestScreen(),
    ),
  );
}

4)