需求

移動裝置上最重要的資訊之一就是電池電量了，所以就來讀取一下電池電量吧!!

battery_plus - Readme

可以讀取有關運行應用程式的裝置的電池的各種資訊。

// Import package
import 'package:battery_plus/battery_plus.dart';

// Instantiate it
var battery = Battery();

// Access current battery level
print(await battery.batteryLevel);

// Be informed when the state (full, charging, discharging) changes
battery.onBatteryStateChanged.listen((BatteryState state) {
  // Do something with new state
});

battery_plus - Install

直接在 pubspec.yaml 加上 battery_plus: ^4.0.2，然後pub get 

dependencies:
  battery_plus: ^4.0.2

battery_plus - Example

在 /lib/main.dart 加入 程式
import 'package:battery_plus/battery_plus.dart';
宣告和初始化

class _MyHomePageState extends State<MyHomePage> {
  final Battery _battery = Battery();
  BatteryState? _batteryState;
 ...
 
void initState() {
        _battery.batteryState.then(_updateBatteryState);
        _batteryStateSubscription =
        _battery.onBatteryStateChanged.listen(_updateBatteryState);
}

void _updateBatteryState(BatteryState state) {
    if (_batteryState == state) return;
    setState(() {
      _batteryState = state;
    });
  }

//讀取電量
Text(
              '$_batteryState',
              style: const TextStyle(fontSize: 24),
            ),
            const SizedBox(height: 24),
            ElevatedButton(
              onPressed: () {
                _battery.batteryLevel.then(
                      (batteryLevel) {
                    showDialog<void>(
                      context: context,
                      builder: (_) => AlertDialog(
                        content: Text('鐵人賽電量 : $batteryLevel%'),
                        actions: <Widget>[
                          TextButton(
                            onPressed: () {
                              Navigator.pop(context);
                            },
                            child: const Text('完賽'),
                          )
                        ],
                      ),
                    );
                  },
                );
              },
              child: const Text('Day22 鐵人賽電量'),
            ),

//讀取是否為省電模式
    ElevatedButton(
              onPressed: () {
                _battery.isInBatterySaveMode.then(
                      (isInPowerSaveMode) {
                    showDialog<void>(
                      context: context,
                      builder: (_) => AlertDialog(
                        title: const Text(
                          '是鐵人賽省電模式嗎?',
                          style: TextStyle(fontSize: 20),
                        ),
                        content: Text(
                          (isInPowerSaveMode == true)? '是' : '否',
                          style: const TextStyle(fontSize: 18),
                        ),
                        actions: <Widget>[
                          TextButton(
                            onPressed: () {
                              Navigator.pop(context);
                            },
                            child: const Text('完賽去'),
                          )
                        ],
                      ),
                    );
                  },
                );
              },
              child: const Text('是鐵人賽省電模式嗎?'),
            )

執行結果

讀取電量

是否為省電模式

心得

是不是簡單又方便，就可以讀取電池的電量和狀態呀!