import 'package:flutter/material.dart';
import 'package:flutter/services.dart'; // 导入 services.dart 以使用 MethodChannel

class BatteryLevelScreen extends StatefulWidget {
  const BatteryLevelScreen({super.key});

  @override
  State<BatteryLevelScreen> createState() => _BatteryLevelScreenState();
}

class _BatteryLevelScreenState extends State<BatteryLevelScreen> {
  static const MethodChannel _platform = MethodChannel('samples.flutter.dev/battery');
  String _batteryLevel = '未知电池电量.';

  Future<void> _getBatteryLevel() async {
    String batteryLevel;
    try {
      // 调用原生方法 'getBatteryLevel'
      final int result = await _platform.invokeMethod('getBatteryLevel');
      batteryLevel = '电池电量: $result%';
    } on PlatformException catch (e) {
      batteryLevel = "获取电池电量失败: '${e.message}'.";
    }

    setState(() {
      _batteryLevel = batteryLevel;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('获取电池电量'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(_batteryLevel),
            const SizedBox(height: 20),
            ElevatedButton(
              onPressed: _getBatteryLevel,
              child: const Text('获取电池电量'),
            ),
          ],
        ),
      ),
    );
  }
}

void main() {
  runApp(const MaterialApp(home: BatteryLevelScreen()));
}

// MainActivity.kt (Kotlin)
package com.example.flutter_app

import io.flutter.embedding.android.FlutterActivity
import io.flutter.embedding.engine.FlutterEngine
import io.flutter.plugin.common.MethodChannel
import android.content.Context
import android.content.ContextWrapper
import android.content.Intent
import android.content.IntentFilter
import android.os.BatteryManager
import android.os.Build.VERSION
import android.os.Build.VERSION_CODES

class MainActivity: FlutterActivity() {
  private val CHANNEL = "samples.flutter.dev/battery"

  override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
    super.configureFlutterEngine(flutterEngine)
    MethodChannel(flutterEngine.dartExecutor.binaryMessenger, CHANNEL).setMethodCallHandler {
      call, result ->
      if (call.method == "getBatteryLevel") {
        val batteryLevel = getBatteryLevel()

        if (batteryLevel != -1) {
          result.success(batteryLevel)
        } else {
          result.error("UNAVAILABLE", "Battery level not available.", null)
        }
      } else {
        result.notImplemented()
      }
    }
  }

  private fun getBatteryLevel(): Int {
    val batteryLevel: Int
    if (VERSION.SDK_INT >= VERSION_CODES.LOLLIPOP) {
      val batteryManager = getSystemService(Context.BATTERY_SERVICE) as BatteryManager
      batteryLevel = batteryManager.getIntProperty(BatteryManager.BATTERY_PROPERTY_CAPACITY)
    } else {
      val intent = ContextWrapper(applicationContext).registerReceiver(null, IntentFilter(Intent.ACTION_BATTERY_CHANGED))
      batteryLevel = intent!!.getIntExtra(BatteryManager.EXTRA_LEVEL, -1) * 100 / intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1)
    }

    return batteryLevel
  }
}

// AppDelegate.swift (Swift)
import UIKit
import Flutter

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    let controller : FlutterViewController = window?.rootViewController as! FlutterViewController
    let batteryChannel = FlutterMethodChannel(name: "samples.flutter.dev/battery",
                                              binaryMessenger: controller.binaryMessenger)

    batteryChannel.setMethodCallHandler {
      (call: FlutterMethodCall, result: @escaping FlutterResult) -> Void in
      // This method is invoked on the UI thread.
      // Handle battery messages.
      guard call.method == "getBatteryLevel" else {
        result(FlutterMethodNotImplemented)
        return
      }
      self.receiveBatteryLevel(result: result)
    }

    GeneratedPluginRegistrant.register(with: self)
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }

  private func receiveBatteryLevel(result: FlutterResult) {
    let device = UIDevice.current
    device.isBatteryMonitoringEnabled = true
    if device.batteryState == .unknown {
      result(FlutterError(code: "UNAVAILABLE",
                          message: "Battery info unavailable",
                          details: nil))
    } else {
      result(Int(device.batteryLevel * 100))
    }
  }
}

dependencies:
  flutter:
    sdk: flutter
  image_picker: ^1.0.7 # 使用最新版本

import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
import 'dart:io'; // 用于 File 对象

class ImagePickerScreen extends StatefulWidget {
  const ImagePickerScreen({super.key});

  @override
  State<ImagePickerScreen> createState() => _ImagePickerScreenState();
}

class _ImagePickerScreenState extends State<ImagePickerScreen> {
  File? _imageFile; // 存储选择的图片文件
  final ImagePicker _picker = ImagePicker();

  Future<void> _pickImage(ImageSource source) async {
    try {
      final XFile? pickedFile = await _picker.pickImage(source: source);
      if (pickedFile != null) {
        setState(() {
          _imageFile = File(pickedFile.path);
        });
      }
    } catch (e) {
      print('Error picking image: $e');
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('选择图片失败: $e')),
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('图片选择器示例'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            _imageFile == null
                ? const Text('未选择图片')
                : Image.file(
                    _imageFile!,
                    width: 200,
                    height: 200,
                    fit: BoxFit.cover,
                  ),
            const SizedBox(height: 20),
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceEvenly,
              children: [
                ElevatedButton.icon(
                  onPressed: () => _pickImage(ImageSource.gallery),
                  icon: const Icon(Icons.photo_library),
                  label: const Text('从相册选择'),
                ),
                ElevatedButton.icon(
                  onPressed: () => _pickImage(ImageSource.camera),
                  icon: const Icon(Icons.camera_alt),
                  label: const Text('拍照'),
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }
}

void main() {
  runApp(const MaterialApp(home: ImagePickerScreen()));
}