iOS 앱에서 최초 카메라를 사용할건지 물어 볼 때 사용자가 쓰지 않는다고 하면 ㅡ,.ㅡ;;

나중에 카메라에서 검은 화면이 뜨게 됨 ㅋㅋ

카메라를 안 쓴다고 했으면 쓰지 말던지, 필요하면 다시 설정해라! 라고 알려줄 필요가 있음.

이 부분을 위한 설정 값을 읽어와서 분기처리 하는 샘플 코드~

/*
// Media types
AVF_EXPORT NSString *const AVMediaTypeVideo    NS_AVAILABLE(10_7, 4_0);
AVF_EXPORT NSString *const AVMediaTypeAudio    NS_AVAILABLE(10_7, 4_0);
AVF_EXPORT NSString *const AVMediaTypeText    NS_AVAILABLE(10_7, 4_0);
AVF_EXPORT NSString *const AVMediaTypeClosedCaption    NS_AVAILABLE(10_7, 4_0);
AVF_EXPORT NSString *const AVMediaTypeSubtitle    NS_AVAILABLE(10_7, 4_0);
AVF_EXPORT NSString *const AVMediaTypeTimecode    NS_AVAILABLE(10_7, 4_0);
AVF_EXPORT NSString *const AVMediaTypeMetadata    NS_AVAILABLE(10_8, 6_0);
AVF_EXPORT NSString *const AVMediaTypeMuxed    NS_AVAILABLE(10_7, 4_0);
*/

AVAuthorizationStatus status = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
if(status == AVAuthorizationStatusAuthorized)
{
    // authorized
    NSLog(@"authorized");
}
else if(status == AVAuthorizationStatusDenied)
{
    // denied
    NSLog(@"denied");
}
else if(status == AVAuthorizationStatusRestricted)
{
    // restricted
    NSLog(@"restricted");
}
else if(status == AVAuthorizationStatusNotDetermined)
{
    // not determined
    NSLog(@"not determined");
    
    [AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo completionHandler:^(BOOL granted) {
        if(granted){ // Access has been granted ..do something
                
        } else { // Access denied ..do something
                
        }
    }];
}

[참조] https://developer.apple.com/library/mac/documentation/AVFoundation/Reference/AVCaptureDevice_Class/index.html

[참조] https://developer.apple.com/library/mac/documentation/AVFoundation/Reference/AVFoundation_Constants/index.html

[출처] http://stackoverflow.com/questions/20464631/detect-permission-of-camera-on-ios