iOS中应用内添加指纹识别的实例代码

LAContext *context = [[LAContext alloc] init];  NSError *error = nil;  //验证是否支持指纹识别  if ([context canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&error]) {    NSLog(@"支持指纹识别的应用");    //验证身份    [context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics localizedReason:NSLocalizedString(@"需要指纹来验证你的身份", @"hello") reply:^(BOOL success, NSError *error) {      if (success) {        NSLog(@"成功");      } else {        switch (error.code) {          case LAErrorUserCancel:            NSLog(@"用户取消了授权 - %@", error.localizedDescription);            break;          case LAErrorUserFallback:            NSLog(@"用户点击了“输入密码”按钮 - %@", error.localizedDescription);            break;          case LAErrorAuthenticationFailed:            NSLog(@"您已授权失败3次 - %@", error.localizedDescription);            break;          case LAErrorTouchIDLockout:            NSLog(@"指纹被锁定 - %@", error.localizedDescription);            break;          case LAErrorSystemCancel:            NSLog(@"应用程序进入后台 - %@", error.localizedDescription);            break;          default:            NSLog(@"++%@--%zd", error.localizedDescription, error.code);            break;        }      }    }];  } else {    switch (error.code) {      case LAErrorPasscodeNotSet:        NSLog(@"未设置密码 - %@", error.localizedDescription);        break;      case LAErrorTouchIDNotEnrolled:        NSLog(@"未注册 Touch ID - %@", error.localizedDescription);        break;      case kLAErrorTouchIDNotAvailable:        NSLog(@"该设备不支持 Touch ID - %@", error.localizedDescription);        break;      default:        NSLog(@"--%@--%zd", error.localizedDescription, error.code);        break;    }  }