flutter_shuqi/lib/pages/reader/battery_view.dart

import 'package:flutter/material.dart';
import 'package:device_info/device_info.dart';
import 'dart:io';
import 'package:battery_plus/battery_plus.dart';
import 'package:shuqi/public.dart';

class BatteryView extends StatefulWidget {
  @override
  _BatteryViewState createState() => _BatteryViewState();
}

class _BatteryViewState extends State<BatteryView> {
  double batteryLevel = 0;

  @override
  void initState() {
    super.initState();

    getBatteryLevel();
  }

  getBatteryLevel() async {
    DeviceInfoPlugin deviceInfo = DeviceInfoPlugin();
    if (Platform.isAndroid) {
      var androidInfo = await deviceInfo.androidInfo;
      if (!androidInfo.isPhysicalDevice) {
        return;
      }
    }
    if (Platform.isIOS) {
      var iosInfo = await deviceInfo.iosInfo;
      if (!iosInfo.isPhysicalDevice) {
        return;
      }
    }
    var battery = Battery();
    var level = await battery.batteryLevel;
    battery.onBatteryStateChanged.listen((BatteryState state) {
      // Do something with new state
    });
    setState(() {
      this.batteryLevel = level / 100.0;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      width: 27,
      height: 12,
      child: Stack(
        children: <Widget>[
          Image.asset('assets/img/reader_battery.png'),
          Container(
            margin: EdgeInsets.fromLTRB(2, 2, 2, 2),
            width: 20 * batteryLevel,
            color: SQColor.golden,
          )
        ],
      ),
    );
  }
}