Flutter实现手电筒亮度修改

在许多应用场景中，手电筒功能不仅需要开关灯，还希望可以调节亮度。Flutter 本身没有提供直接操作手电筒的 API，但我们可以通过 Platform Channel 调用 Android/iOS 原生接口，实现开关灯和亮度控制。

本文我们将详细讲解实现思路和方法，让读者可以自己写出一个类似的插件

功能需求

开/关手电筒
调节亮度（0~1 的百分比）
获取当前亮度和手电状态
获取最大亮度等级（Android 13+ 有真实等级，iOS 默认 100）
自动开关灯逻辑：亮度 > 0 自动开灯，亮度 = 0 自动关灯
跨平台支持：Android 13+ 支持亮度，旧版本 Android 仅开灯；iOS 支持 0~1 小数亮度

实现原理

Android 原理实现

Android 使用 Camera2 API 控制手电筒：

开关手电筒

复制代码

cameraManager.setTorchMode(cameraId, true); // 开灯
cameraManager.setTorchMode(cameraId, false); // 关灯

调节亮度（Android 13+）

复制代码

cameraManager.turnOnTorchWithStrengthLevel(cameraId, torchLevel);

iOS原理实现

iOS 使用 AVCaptureDevice 控制摄像头 LED：

开关手电筒

复制代码

FlashlightBrightness.instance.flashOn();          // 开灯
FlashlightBrightness.instance.flashOff();         // 关灯

调节亮度

复制代码

FlashlightBrightness.instance.setBrightness(0.5); // 50%亮度

实现步骤

创建一个Flutter 插件

复制代码

flutter create --template=plugin --platforms=android,ios -a java flashlight_brightness

Flutter插件lib配置

1.文件预览

复制代码

lib/
├─ flashlight_brightness.dart              # 插件主入口，提供给用户的 API
├─ flashlight_brightness_method_channel.dart  # MethodChannel 平台实现（Android/iOS 调用）
└─ flashlight_brightness_platform_interface.dart # 抽象平台接口，定义公共方法

作用：

flashlight_brightness.dart：Flutter 层调用统一接口，无需关心平台差异。
flashlight_brightness_platform_interface.dart：定义接口，支持未来可能增加其他平台（web、macOS 等）。
flashlight_brightness_method_channel.dart：通过 MethodChannel 调用 Android/iOS 原生代码，实现接口。

2.创建平台接口

在 lib/flashlight_brightness_platform_interface.dart：

复制代码

import 'package:plugin_platform_interface/plugin_platform_interface.dart';
 
import 'flashlight_brightness_method_channel.dart';
 
/// @class FlashlightBrightnessPlatform
/// @description 定义插件接口，支持多平台实现
abstract class FlashlightBrightnessPlatform extends PlatformInterface {
  FlashlightBrightnessPlatform() : super(token: _token);
 
  static final Object _token = Object();
 
  static FlashlightBrightnessPlatform _instance =
      MethodChannelFlashlightBrightness();
 
  /// 默认实例，MethodChannel 实现
  static FlashlightBrightnessPlatform get instance => _instance;
 
  static set instance(FlashlightBrightnessPlatform instance) {
    PlatformInterface.verifyToken(instance, _token);
    _instance = instance;
  }
 
  /// 获取 Android/iOS 版本（字符串）
  Future<String?> getPlatformVersion() {
    throw UnimplementedError('getPlatformVersion() has not been implemented.');
  }
 
  /// 初始化插件
  Future<void> init() {
    throw UnimplementedError('init() has not been implemented.');
  }
 
  /// 查询手电筒是否点亮
  Future<bool?> isTorched() {
    throw UnimplementedError('isTorched() has not been implemented.');
  }
 
  /// 打开手电筒
  Future<void> flashOn() {
    throw UnimplementedError('flashOn() has not been implemented.');
  }
 
  /// 关闭手电筒
  Future<void> flashOff() {
    throw UnimplementedError('flashOff() has not been implemented.');
  }
 
  /// 获取亮度百分比 0~1
  Future<double?> getBrightness() {
    throw UnimplementedError('getBrightness() has not been implemented.');
  }
 
  /// 设置亮度百分比 0~1
  Future<void> setBrightness(double value) {
    throw UnimplementedError('setBrightness() has not been implemented.');
  }
 
  /// 获取设备最大等级
  Future<int?> getMaxLevel() {
    throw UnimplementedError('getMaxLevel() has not been implemented.');
  }
 
  /// 销毁插件
  Future<void> dispose() {
    throw UnimplementedError('dispose() has not been implemented.');
  }
}

说明：

所有方法都是抽象的，必须由具体平台实现。
_instance 默认指向 MethodChannel 实现。

3.创建 MethodChannel 实现

在 lib/flashlight_brightness_method_channel.dart：

复制代码

import 'package:flutter/services.dart';
import 'flashlight_brightness_platform_interface.dart';
 
/// @class MethodChannelFlashlightBrightness
/// @description 通过 MethodChannel 与原生通信实现 FlashlightBrightnessPlatform
class MethodChannelFlashlightBrightness extends FlashlightBrightnessPlatform {
  final MethodChannel _channel = const MethodChannel('flashlight_brightness');
 
  @override
  Future<String?> getPlatformVersion() async {
    return await _channel.invokeMethod('getPlatformVersion');
  }
 
  @override
  Future<void> init() async {
    await _channel.invokeMethod('init');
  }
 
  @override
  Future<bool?> isTorched() async {
    return await _channel.invokeMethod('isTorched');
  }
 
  @override
  Future<void> flashOn() async {
    await _channel.invokeMethod('flashOn');
  }
 
  @override
  Future<void> flashOff() async {
    await _channel.invokeMethod('flashOff');
  }
 
  @override
  Future<double?> getBrightness() async {
    return await _channel.invokeMethod('getPercent');
  }
 
  @override
  Future<void> setBrightness(double value) async {
    if (value < 0) value = 0;
    if (value > 1) value = 1;
    await _channel.invokeMethod('setPercent', value);
  }
 
  @override
  Future<int?> getMaxLevel() async {
    return await _channel.invokeMethod('maxLevel');
  }
 
  @override
  Future<void> dispose() async {
    await _channel.invokeMethod('dispose');
  }
}

说明：

使用 MethodChannel 调用原生 Android/iOS 方法。
参数和返回值都做了简单映射（比如亮度百分比 0~1）。

4.创建插件主入口

在 lib/flashlight_brightness.dart：

复制代码

import 'flashlight_brightness_platform_interface.dart';
 
/// @class FlashlightBrightness
/// @description Flutter 端插件封装，提供统一方法给业务层调用
class FlashlightBrightness {
  FlashlightBrightness._privateConstructor() {
    _platform.init(); // 自动初始化
  }
 
  static final FlashlightBrightness instance =
      FlashlightBrightness._privateConstructor(); // 单例模式
 
  final FlashlightBrightnessPlatform _platform =
      FlashlightBrightnessPlatform.instance;
 
  /// 获取系统版本
  Future<String?> getPlatformVersion() => _platform.getPlatformVersion();
 
  /// 初始化插件
  Future<void> init() => _platform.init();
 
  /// 手电筒是否点亮
  Future<bool?> isTorched() => _platform.isTorched();
 
  /// 打开手电筒
  Future<void> flashOn() => _platform.flashOn();
 
  /// 关闭手电筒
  Future<void> flashOff() => _platform.flashOff();
 
  /// 获取亮度百分比 0~1
  Future<double?> getBrightness() => _platform.getBrightness();
 
  /// 设置亮度百分比 0~1
  Future<void> setBrightness(double value) => _platform.setBrightness(value);
 
  /// 获取设备最大等级
  Future<int?> getMaxLevel() => _platform.getMaxLevel();
 
  /// 销毁插件
  Future<void> dispose() => _platform.dispose();
}

说明：

提供统一的 Flutter API，隐藏平台差异。
用户只需要导入 flashlight_brightness.dart 即可使用插件功能。
使用单例模式 instance，确保全局只有一个插件实例。

Android 手电筒亮度控制实现方式

1.文件预览

复制代码

android/src/main/java/com/example/flashlight_brightness/
├─ FlashlightBrightnessConstants.java     # 方法名与关键常量
├─ FlashlightBrightnessController.java    # 具体的手电筒实现逻辑
└─ FlashlightBrightnessPlugin.java        # Flutter 插件入口，MethodChannel 分发

作用：

FlashlightBrightnessConstants.java：规范接口，集中管理 MethodChannel 的方法名
FlashlightBrightnessController.java：手电筒控制逻辑，不影响 MethodChannel
FlashlightBrightnessPlugin.java：MethodChannel 入口，收 Flutter 调用 → 分发给 Controller → 返回结果给 Flutter

2.定义方法变量

在android/src/main/java/com/example/flashlight_brightness/FlashlightBrightnessConstants.java:

复制代码

package com.example.flashlight_brightness;
 
/**
 * @class FlashlightBrightnessConstants
 * @description 定义插件中使用的所有方法名常量，统一管理 Flutter 与 Android 端通信的 key
 * @features
 *   - 提供插件方法常量
 *   - 避免字符串硬编码
 *   - 提供亮度控制相关常量
 */
public final class FlashlightBrightnessConstants {
 
  private FlashlightBrightnessConstants() {} // 私有构造，防止实例化
 
  // 获取 Android 系统版本
  public static final String VERSION = "getPlatformVersion";
 
  // 初始化 FlashlightBrightnessController
  public static final String INIT = "init";
 
  // 开灯 / 关灯
  public static final String FLASH_ON = "flashOn";
  public static final String FLASH_OFF = "flashOff";
 
  // 获取 / 设置亮度百分比（0~1）
  public static final String SET_PERCENT = "setPercent";
  public static final String GET_PERCENT = "getPercent";
 
  // 获取设备支持的最大 torch level
  public static final String MAX_LEVEL = "maxLevel";
 
  // 查询手电筒是否已点亮
  public static final String IS_TORCHED = "isTorched";
 
  // 销毁 FlashlightBrightnessController
  public static final String DISPOSE = "dispose";
}

3.配置手电筒配置逻辑

在android/src/main/java/com/example/flashlight_brightness/FlashlightBrightnessController.java:

主要功能

获取亮度等级
- Android 13+：获取真实最大等级
- Android 6~12：等级为1
获取手电筒亮度
- 当前的亮度等级/最大亮度等级
设置手电筒亮度
- 设置值范围0~1。
  - 0：关闭手电筒
- 亮度值*最大亮度等级并取整
  
  package com.example.flashlight_brightness;
  
  import android.annotation.TargetApi;
  import android.content.Context;
  import android.hardware.camera2.CameraCharacteristics;
  import android.hardware.camera2.CameraManager;
  import android.os.Build;
  import android.util.Log;
  
  /**
  - @class FlashlightBrightnessController
  - @description Android 手电筒控制类，支持亮度控制
  - @features
  - 复制代码
```
      - 获取 / 设置亮度（百分比 0~1）
```
  - 复制代码
```
      - 打开 / 关闭手电筒
```
  - 复制代码
```
      - 获取最大亮度等级
```
  - 复制代码
```
      - Android 13+ 支持多级亮度控制
```
  - 复制代码
```
      - Android 6~12 基础开关手电筒兼容
```
  */
  @TargetApi(Build.VERSION_CODES.LOLLIPOP)
  public class FlashlightBrightnessController {
  
  private final CameraManager cameraManager;
  private String cameraId;
  
  private boolean isTorched = false; // 当前是否点亮
  private int torchLevel = 1; // 当前亮度等级（整数）
  private int maxLevel = 1; // 设备支持的最大亮度等级
  
  /**
  - Torch 回调监听器
  - 用于监听亮度和状态变化
    */
    private final CameraManager.TorchCallback torchCallback = new CameraManager.TorchCallback() {
    @Override
    public void onTorchStrengthLevelChanged(String id, int newStrengthLevel) {
    torchLevel = newStrengthLevel;
    }
  复制代码
```
@Override
public void onTorchModeChanged(String id, boolean enabled) {
  isTorched = enabled;
}
```
  };
  
  /**
  - 构造函数
  - @param context 应用上下文
  - @description 初始化 CameraManager 和 TorchCallback，获取后置摄像头 ID 和最大亮度
    */
    public FlashlightBrightnessController(Context context) {
    cameraManager = (CameraManager) context.getSystemService(Context.CAMERA_SERVICE);
  复制代码
```
try {
  for (String id : cameraManager.getCameraIdList()) {
    CameraCharacteristics cs = cameraManager.getCameraCharacteristics(id);
    Integer lens = cs.get(CameraCharacteristics.LENS_FACING);
    if (lens != null && lens == CameraCharacteristics.LENS_FACING_BACK) {
      cameraId = id;

      // Android 13+ 获取真实最大等级
      if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
        maxLevel = cameraManager.getTorchStrengthLevel(cameraId);
      } else {
        maxLevel = 1; // Android 6~12 无多级亮度
      }
      break;
    }
  }

  // 注册回调监听
  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
    cameraManager.registerTorchCallback(torchCallback, null);
  }

} catch (Exception e) {
  Log.e("FlashlightBrightnessController", "Init failed", e);
}
```
  }
  
  /**
  - @return 当前手电筒是否点亮
    */
    public boolean isTorched() {
    return isTorched;
    }
  /**
  - @return 设备最大亮度等级
    */
    public int getMaxTorchLevel() {
    return maxLevel;
    }
  /**
  - @return 当前亮度百分比（0~1）
    */
    public double getTorchLevelPercent() {
    if (maxLevel <= 1)
    return isTorched ? 1.0 : 0.0;
    return torchLevel / (double) maxLevel;
    }
  /**
  - 设置亮度百分比并自动开灯
  - @param percent 亮度百分比，范围 0~1
    */
    public void setTorchLevelPercent(double percent) {
    // if (percent < 0.0) percent = 0.0;
    // if (percent > 1.0) percent = 1.0;
    percent = Math.max(0, Math.min(percent, 1)); // 限制在 0~1
    if (percent == 0) {
    // 如果亮度为 0，直接关灯
    flashOff();
    torchLevel = 0;
    return;
    }
  复制代码
```
int level = (int) Math.round(percent * maxLevel);
if (level < 1)
  level = 1;

torchLevel = level;

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
  try {
    cameraManager.turnOnTorchWithStrengthLevel(cameraId, torchLevel);
    isTorched = true;
  } catch (Exception e) {
    Log.e("FlashlightBrightnessController", "setTorchLevelPercent failed", e);
  }
} else {
  flashOn(); // Android 6~12 只能开灯，不支持亮度
}
```
  }
  
  /**
  - 开灯
    */
    public void flashOn() {
    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M)
    return;
  复制代码
```
if (!isTorched) {
  try {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU && maxLevel > 1) {
      cameraManager.turnOnTorchWithStrengthLevel(cameraId, torchLevel);
    } else {
      cameraManager.setTorchMode(cameraId, true);
    }
    isTorched = true;
  } catch (Exception e) {
    Log.e("FlashlightBrightnessController", "flashOn failed", e);
  }
}
```
  }
  
  /**
  - 关灯
    */
    public void flashOff() {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && isTorched) {
    try {
    cameraManager.setTorchMode(cameraId, false);
    isTorched = false;
    } catch (Exception e) {
    Log.e("FlashlightBrightnessController", "flashOff failed", e);
    }
    }
    }
  /**
  - 注销回调并关闭手电筒
    */
    public void dispose() {
    try {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
    cameraManager.unregisterTorchCallback(torchCallback);
    }
    } catch (Exception ignored) {
    }
    flashOff();
    }
    }

4.Flutter ↔ Android 通信桥梁配置

在android/src/main/java/com/example/flashlight_brightness/FlashlightBrightnessPlugin.java:

主要作用：

Flutter ↔ Android 通信桥梁

分发方法到 Controller

package com.example.flashlight_brightness;

import android.content.Context;
import android.os.Build;

import androidx.annotation.NonNull;

import io.flutter.embedding.engine.plugins.FlutterPlugin;
import io.flutter.plugin.common.MethodCall;
import io.flutter.plugin.common.MethodChannel;

/**

@class FlashlightBrightnessPlugin
@description Flutter 插件入口，实现 MethodChannel 与 Android 原生通信
@features
复制代码
```
      - 注册 MethodChannel
```

复制代码

      - 分发 Flutter 调用到 FlashlightBrightnessController

复制代码
```
      - 提供百分比亮度接口
```
复制代码
```
      - 提供最大亮度等级查询
```

复制代码

      - 管理生命周期（初始化、销毁）

*/
public class FlashlightBrightnessPlugin implements FlutterPlugin, MethodChannel.MethodCallHandler {

复制代码

private MethodChannel channel;
private Context context;
private FlashlightBrightnessController flashlightController;

@Override
public void onAttachedToEngine(@NonNull FlutterPluginBinding binding) {
  channel = new MethodChannel(binding.getBinaryMessenger(), "flashlight_brightness");
  channel.setMethodCallHandler(this);
  context = binding.getApplicationContext();
  // 自动初始化
  ensureController();
}

@Override
public void onMethodCall(@NonNull MethodCall call, @NonNull MethodChannel.Result result) {

  switch (call.method) {

    case FlashlightBrightnessConstants.VERSION:
      result.success("Android " + Build.VERSION.RELEASE);
      break;

    case FlashlightBrightnessConstants.INIT:
      if (flashlightController == null) {
        flashlightController = new FlashlightBrightnessController(context);
      }
      result.success(true);
      break;

    case FlashlightBrightnessConstants.IS_TORCHED:
      // 自动初始化
      ensureController();
      result.success(flashlightController.isTorched());
      break;

    case FlashlightBrightnessConstants.FLASH_ON:
      ensureController();
      flashlightController.flashOn();
      result.success(true);
      break;

    case FlashlightBrightnessConstants.FLASH_OFF:
      ensureController();
      flashlightController.flashOff();
      result.success(true);
      break;

    case FlashlightBrightnessConstants.GET_PERCENT:
      ensureController();
      result.success(flashlightController.getTorchLevelPercent());
      break;

    case FlashlightBrightnessConstants.SET_PERCENT:
      ensureController();
      Object arg = call.arguments;
      double percent = 1.0;
      if (arg instanceof Number) {
        percent = ((Number) arg).doubleValue();
      }
      flashlightController.setTorchLevelPercent(percent);
      result.success(true);
      break;

    case FlashlightBrightnessConstants.MAX_LEVEL:
      ensureController();
      result.success(flashlightController.getMaxTorchLevel());
      break;

    case FlashlightBrightnessConstants.DISPOSE:
      if (flashlightController != null) {
        flashlightController.dispose();
        flashlightController = null;
      }
      result.success(true);
      break;

    default:
      result.notImplemented();
  }
}

/**
 * 确保 flashlightController 已初始化
 */
private void ensureController() {
  if (flashlightController == null) {
    flashlightController = new FlashlightBrightnessController(context);
  }
}

@Override
public void onDetachedFromEngine(@NonNull FlutterPluginBinding binding) {
  channel.setMethodCallHandler(null);
}

}

至此，Android配置就完成了

iOS 手电筒亮度控制实现方式

1.文件预览

复制代码

flashlight_brightness/
 └─ ios/
     └─ Classes/
         ├─ FlashlightBrightnessPlugin.swift        // Flutter 插件入口
         ├─ FlashlightBrightnessController.swift     // 手电筒控制核心逻辑
         └─ FlashlightBrightnessConstants.swift      // 方法名常量（与 Android 对应）

作用：

FlashlightBrightnessConstants.swift ：负责统一 iOS MethodChannel 方法名
FlashlightBrightnessController.swift：控制 iOS 手电筒亮度核心逻辑
FlashlightBrightnessPlugin.swift：插件入口：接收 Flutter 调用 → 分发给 Controller

2.定义方法变量

在ios/Classes/FlashlightBrightnessConstants.swift

复制代码

//
//  FlashlightBrightnessConstants.swift
//  flashlight_brightness
//
//  定义 Flutter 与 iOS 通信的常量方法名
//
 
import Foundation
 
enum FlashlightBrightnessConstants {
    static let version = "getPlatformVersion"
    static let initPlugin = "init"
     
    static let flashOn = "flashOn"
    static let flashOff = "flashOff"
     
    static let setPercent = "setPercent"
    static let getPercent = "getPercent"
     
    static let maxLevel = "maxLevel"
    static let isTorched = "isTorched"
     
    static let dispose = "dispose"
}

3.配置手电筒配置逻辑

在ios/Classes/FlashlightBrightnessController.swift

复制代码

//
//  FlashlightBrightnessController.swift
//  flashlight_brightness
//
//  封装手电筒控制逻辑，支持开关和亮度控制
//
 
import AVFoundation
import UIKit
 
class FlashlightBrightnessController {
     
    private let device = AVCaptureDevice.default(for: .video)
    private var currentBrightness: Float = 1.0
     
    /// 判断设备是否有手电筒
    var hasTorch: Bool {
        return device?.hasTorch ?? false
    }
     
    /// 当前是否点亮
    var isTorched: Bool {
        guard let device = device else { return false }
        return device.isTorchActive
    }
     
    /// 最大亮度等级（iOS 恒定为 1.0）
    var maxLevel: Int {
        return 100
    }
     
    /// 获取当前亮度百分比 0~1
    var brightness: Float {
        return currentBrightness
    }
     
    /// 设置亮度百分比 0~1 并自动开灯
    func setBrightness(_ percent: Float) {
        guard hasTorch, let device = device else { return }
        let level = min(max(percent, 0.0), 1.0)
        if level == 0 {
            // 亮度为0，自动关灯
            flashOff()
            currentBrightness = 0
            return
        }
        currentBrightness = level
         
        do {
            try device.lockForConfiguration()
            try device.setTorchModeOn(level: level)
            device.unlockForConfiguration()
        } catch {
            print("Failed to set torch brightness: \(error)")
        }
    }
     
    /// 打开手电筒（使用当前亮度）
    func flashOn() {
        guard hasTorch, let device = device else { return }
        do {
            try device.lockForConfiguration()
            if !device.isTorchActive {
                try device.setTorchModeOn(level: currentBrightness)
            }
            device.unlockForConfiguration()
        } catch {
            print("Failed to turn on torch: \(error)")
        }
    }
     
    /// 关闭手电筒
    func flashOff() {
        guard hasTorch, let device = device else { return }
        do {
            try device.lockForConfiguration()
            device.torchMode = .off
            device.unlockForConfiguration()
        } catch {
            print("Failed to turn off torch: \(error)")
        }
    }
     
    /// 销毁控制器（iOS 不需要额外操作）
    func dispose() {
        flashOff()
    }

4.接收 Flutter 调用 → 分发给 Controller 配置

在ios/Classes/FlashlightBrightnessPlugin.swift

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//
//  FlashlightBrightnessPlugin.swift
//  flashlight_brightness
//
//  Flutter 插件入口，注册 MethodChannel 并分发方法
//
 
import Flutter
import UIKit
 
public class FlashlightBrightnessPlugin: NSObject, FlutterPlugin {
     
    /// 控制器实例，可变变量
    private var controller: FlashlightBrightnessController?
     
    public static func register(with registrar: FlutterPluginRegistrar) {
        let channel = FlutterMethodChannel(name: "flashlight_brightness", binaryMessenger: registrar.messenger())
        let instance = FlashlightBrightnessPlugin()
        registrar.addMethodCallDelegate(instance, channel: channel)
    }
     
    /// 获取控制器，如果未创建则自动初始化
    private func getController() -&gt; FlashlightBrightnessController {
        if controller == nil {
            controller = FlashlightBrightnessController() // 自动初始化
        }
        return controller!
    }
     
    public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
        // 使用类属性 controller，不再声明 let
        switch call.method {
             
        case FlashlightBrightnessConstants.version:
            result("iOS \(UIDevice.current.systemVersion)")
             
        case FlashlightBrightnessConstants.initPlugin:
            // 已经自动初始化，无需重新赋值
            _ = getController()
            result(true)
             
        case FlashlightBrightnessConstants.isTorched:
            result(controller?.isTorched ?? false)
             
        case FlashlightBrightnessConstants.flashOn:
            getController().flashOn()
            result(true)
             
        case FlashlightBrightnessConstants.flashOff:
            getController().flashOff()
            result(true)
             
        case FlashlightBrightnessConstants.getPercent:
            result(getController().brightness)
             
        case FlashlightBrightnessConstants.setPercent:
            if let arg = call.arguments as? Double {
                getController().setBrightness(Float(arg)) // 自动开灯或关灯
            }
            result(true)
             
        case FlashlightBrightnessConstants.maxLevel:
            result(getController().maxLevel)
             
        case FlashlightBrightnessConstants.dispose:
            controller?.dispose()
            controller = nil
            result(true)
             
        default:
            result(FlutterMethodNotImplemented)
        }
    }
}

至此，iOS配置也就完成了

使用方法

创建单例实例

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import 'package:flashlight_brightness/flashlight_brightness.dart';
final flashlight = FlashlightBrightness.instance;

开启/关闭手电筒

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await flashlight.flashOn();  // 开灯
await flashlight.flashOff(); // 关灯

设置亮度 (0.0 - 1.0)

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// 设置亮度为50%，如果手电未开则会自动开灯
await flashlight.setBrightness(0.5);
 
// 设置亮度为0，会自动关闭手电筒
await flashlight.setBrightness(0.0);

获取当前亮度

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double? brightness = await flashlight.getBrightness(); // 返回0.0~1.0

判断手电筒是否开启

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bool? isOn = await flashlight.isTorched();

获取最大亮度等级

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int? maxLevel = await flashlight.getMaxLevel(); // Android: 5，iOS: 100

释放资源（可选）

复制代码

await flashlight.dispose();