iOS 7.1 imagePicker CameraFlashMode不指示闪光灯状态

我有iPhone应用程序，该应用程序将相机与自定义 View 叠加在一起。
我有一个按钮可以在相机闪光灯模式之间切换，这是代码

switch ([self.imagePickerController cameraFlashMode]) {
    case UIImagePickerControllerCameraFlashModeAuto:
        [self.imagePickerController setCameraFlashMode:UIImagePickerControllerCameraFlashModeOn];
        return @"On";
        break;

    case UIImagePickerControllerCameraFlashModeOn:
        [self.imagePickerController setCameraFlashMode:UIImagePickerControllerCameraFlashModeOff];
        return @"Off";
        break;

    case UIImagePickerControllerCameraFlashModeOff:
        [self.imagePickerController setCameraFlashMode:UIImagePickerControllerCameraFlashModeAuto];
        return @"Auto";
        break;

    default:
        break;
}

这是我的问题:在iOS 7.0x上可以正常工作，但是在iOS 7.1中，无论其实际状态如何，cameraFlashMode属性都将返回UIImagePickerControllerCameraFlashModeAuto。

闪光灯模式确实会改变，但是我没有得到任何指示。
有什么线索吗？
谢谢

最佳答案

我这样解决了:

@property (nonatomic) NSInteger flashMode;

if (_flashMode == UIImagePickerControllerCameraFlashModeAuto)
{
    _flashMode = UIImagePickerControllerCameraFlashModeOff;
}
else if (_flashMode == UIImagePickerControllerCameraFlashModeOff)
{
    _flashMode = UIImagePickerControllerCameraFlashModeOn;
}
else if (_flashMode == UIImagePickerControllerCameraFlashModeOn)
{
    _flashMode = UIImagePickerControllerCameraFlashModeAuto;
}

_cameraPicker.cameraFlashMode = (UIImagePickerControllerCameraFlashMode)_flashMode;

关于iOS 7.1 imagePicker CameraFlashMode不指示闪光灯状态，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/22457097/