Printing the content of a UIView in a UIImage works in simulator but not device

Question

I've been writing an IOS application, and I wish to create an exact copy of a video player, and display this double just below. The user would not be able to interact with that double since it's just a reflection.

For that, I successfully displayed a video (MPMoviePlayerController) in a UIViewer, and I try to copy the content of the view attribute of the player in a UIImage just below.

Here is my code so far :

@interface ViewController ()
    @property (strong, nonatomic) MPMoviePlayerController *player;
    @property (strong, nonatomic) UIImageView *imageView;

    - (UIImage *)screenCapture:(UIView *)view;
@end

@implementation ViewController


- (void)viewDidLoad {
    [super viewDidLoad];

    NSURL *url = [NSURL URLWithString:@"http://xxx.xxx.xx.xx/serenity.mp4"];
    MPMoviePlayerController *player = [[MPMoviePlayerController alloc] initWithContentURL:url];

    self.player = player;

    player.view.frame = CGRectMake(0, 0, 320, 200);
    [self.view addSubview:player.view];
    [self.view bringSubviewToFront:player.view];

    [player prepareToPlay];

    CGRect rect = CGRectMake(0, 310, 320, 200);
    _imageView = [[UIImageView alloc]initWithFrame:rect];

    [self.view addSubview:_imageView];

    NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:0.03 target:self selector:@selector(repeateMethod:) userInfo:nil repeats:YES];
    // repeateMethod calls the snapshot every 0.03 second

}

- (void)repeateMethod:(NSTimer *)timer
{
    _imageView.image = [self screenCapture:_player.view];
}

- (UIImage *)screenCapture:(UIView *)view {
    UIImage *capture;

    [view snapshotViewAfterScreenUpdates: NO];
    UIGraphicsBeginImageContextWithOptions(view.frame.size , NO , 2.0 );

    if ([view respondsToSelector:@selector(drawViewHierarchyInRect:afterScreenUpdates:)]) {
        [view drawViewHierarchyInRect:view.frame afterScreenUpdates:NO];
    } else {
        [view.layer renderInContext:UIGraphicsGetCurrentContext()];
    }

    capture = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return capture;
}
@end

This code works perfectly on the simulator, which gives this result :

https://i.stack.imgur.com/umHsE.png

You can see that i have exactly the behaviour expected : a clone of the video, that is refreshed every 0.03 second.

But when I play this on my iPhone device, i get this :

https://i.stack.imgur.com/6tSZQ.png

As you can see, only the controllers are displayed, but the video's content is completely missing ! I can not understand why since it's working well in the simulator... How would you explain this bug? Do you think it's got to do with Apple policy as a prevention to copy video content? Thanks in advance !

Printing the content of a UIView in a UIImage works in simulator but not device

0 Answers0