import 'package:permission_handler/permission_handler.dart';

// 请求相机权限
final status = await Permission.camera.request();
if (status.isGranted) {
  // 权限已授予
} else if (status.isDenied) {
  // 权限被拒绝
} else if (status.isPermanentlyDenied) {
  // 权限被永久拒绝，需要引导用户到设置页面
  openAppSettings();
}

// 检查权限状态
final locationStatus = await Permission.location.status;

import 'package:flutter_secure_storage/flutter_secure_storage.dart';

final storage = FlutterSecureStorage();

// 存储数据
await storage.write(key: 'token', value: 'user_token_value');

// 读取数据
final token = await storage.read(key: 'token');

// 删除数据
await storage.delete(key: 'token');

// 删除所有数据
await storage.deleteAll();

// 检查键是否存在
final hasToken = await storage.containsKey(key: 'token');

import 'package:local_auth/local_auth.dart';

final localAuth = LocalAuthentication();

// 检查是否支持生物识别
bool canCheckBiometrics = await localAuth.canCheckBiometrics;
List availableBiometrics = await localAuth.getAvailableBiometrics();

// 进行生物识别认证
bool isAuthenticated = await localAuth.authenticate(
  localizedReason: '请验证您的身份',
  options: AuthenticationOptions(
    stickyAuth: true,
    biometricOnly: true,
  ),
);

if (isAuthenticated) {
  // 认证成功
} else {
  // 认证失败
}

import 'package:encrypt/encrypt.dart';

// AES 加密
final key = Key.fromUtf8('32-character-long-key-here!!');
final iv = IV.fromLength(16);
final encrypter = Encrypter(AES(key));

// 加密
final encrypted = encrypter.encrypt('Hello, World!', iv: iv);

// 解密
final decrypted = encrypter.decrypt(encrypted, iv: iv);

// 使用 base64
final encryptedBase64 = encrypted.base64;
final decryptedBase64 = encrypter.decrypt64(encryptedBase64, iv: iv);

import 'package:flutter_keychain/flutter_keychain.dart';

// 保存到 Keychain
await FlutterKeychain.put(key: 'password', value: 'secret123');

// 从 Keychain 读取
final password = await FlutterKeychain.get(key: 'password');

// 从 Keychain 删除
await FlutterKeychain.remove(key: 'password');