ios - 如何处理人脸识别权限警报？

Question

我写了以下代码片段

if ([contextNew canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&error])
{
    [contextNew evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics localizedReason:NSLocalizedString(@"",nil) reply:^(BOOL success, NSError *error)
    {
        if(success)
        {

        }
        else
        {

        }
    }
}

验证人脸后进入成功块。我想处理人脸 id 权限警报。我想获得 face id 的 Yes 或 permission grant 方法。当我们得到相机的 AVAuthorizationStatus 之类的东西时

Answer 1

不确定，这是否能解决您的问题，但我有以下选项来检测LAAuthentication错误类型（在 Swift 中，您需要将其转换为 Objective-C）

laContext.evaluatePolicy(biometricsPolicy, localizedReason: localizedReason, reply: { (isSuccess, error) in
    if let laError = error {
       // handle error
       self.showLAError(laError: laError)
    } else if isSuccess {
      // handle success
    }
})


// function to detect an error type
func showLAError(laError: Error) -> Void {
    
    var message = ""
    
    switch laError {
        
    case LAError.appCancel:
        message = "Authentication was cancelled by application"
        
    case LAError.authenticationFailed:
        message = "The user failed to provide valid credentials"
        
    case LAError.invalidContext:
        message = "The context is invalid"
        
    case LAError.passcodeNotSet:
        message = "Passcode is not set on the device"
        
    case LAError.systemCancel:
        message = "Authentication was cancelled by the system"
        
    case LAError.touchIDLockout:
        message = "Too many failed attempts."
        
    case LAError.touchIDNotAvailable:
        message = "TouchID is not available on the device"
        
    case LAError.userCancel:
        message = "The user did cancel"
        
    case LAError.userFallback:
        message = "The user chose to use the fallback"
        
    default:
        
        if #available(iOS 11.0, *) {
            
            switch laError {
                
            case LAError.biometryNotAvailable:
                message = "Biometry is not available"
                
            case LAError.biometryNotEnrolled:
                message = "Authentication could not start, because biometry has no enrolled identities"
                
            case LAError.biometryLockout:
                message = "Biometry is locked. Use passcode."

            default:
                message = "Did not find error code on LAError object"
            }
            
        }
        message = "Did not find error code on LAError object"
        
        
    }
    
    //return message
    print("LAError message - \(message)")
    
}

这是Objective-C的所有类型的LAError列表

编辑：

如果您正在尝试使用 Simulator，请在此处查看如何测试 Face-Id：

• 我们可以在模拟器中测试 Face ID 吗？

这是工作的Objective-C代码。试试这个，看看：

LAContext *laContext = [[LAContext alloc] init];

NSError *error;

if ([laContext canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&error]) {
    
    if (error != NULL) {
        // handle error
        //[self showError:error];
    } else {
        
        if (@available(iOS 11.0.1, *)) {
            if (laContext.biometryType == LABiometryTypeFaceID) {
                //localizedReason = "Unlock using Face ID"
                NSLog(@"FaceId support");
            } else if (laContext.biometryType == LABiometryTypeTouchID) {
                //localizedReason = "Unlock using Touch ID"
                NSLog(@"TouchId support");
            } else {
                //localizedReason = "Unlock using Application Passcode"
                NSLog(@"No Biometric support");
            }
        } else {
            // Fallback on earlier versions
        }
        
        
        [laContext evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics localizedReason:@"Test Reason" reply:^(BOOL success, NSError * _Nullable error) {
            
            if (error != NULL) {
                // handle error
            } else if (success) {
                // handle success response
            } else {
                // handle false response
            }
        }];
    }
}