关于窗口层次结构的警告

我的调试器中出现这样的警告，这是什么意思？

Warning: Attempt to present <RootViewViewController: 0x134ce9c0> on <MovieViewController: 0xa967290> whose view is not in the window hierarchy!

我也做MovieViewController作为 Storyboard 中的初始视图控制器，我也使用 ARC。

注意：当我添加两个时，这不会出现[super viewDidLoad];1 在最低部分的中间viewDidLoad，这是错误的。

这是我的实现MovieViewController:

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.view.backgroundColor = [UIColor whiteColor];

    NSString *moviePath = [[NSBundle mainBundle] pathForResource:@"gameopening" ofType:@"m4v"];
    self.moviePlayer = [AVPlayer playerWithURL:[NSURL fileURLWithPath:moviePath]];
    [self.moviePlayer play];

    // Create and configure AVPlayerLayer
    AVPlayerLayer *moviePlayerLayer = [AVPlayerLayer playerLayerWithPlayer:self.moviePlayer];
    moviePlayerLayer.bounds = CGRectMake(0, 0, 1024, 768);
    moviePlayerLayer.position = CGPointMake(515,385);
    moviePlayerLayer.borderColor = [UIColor clearColor].CGColor;
    moviePlayerLayer.borderWidth = 3.0;
    moviePlayerLayer.shadowOffset = CGSizeMake(0, 3);
    moviePlayerLayer.shadowOpacity = 0.80;

    // Add perspective transform

    [self.view.layer addSublayer:moviePlayerLayer];    

    [self performSelector:@selector(loadingView) withObject:nil afterDelay:33.0];  
    UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTapGesture:)];
    tapGesture.numberOfTapsRequired = 1;
    [self.view addGestureRecognizer:tapGesture];

}

- (void)handleTapGesture:(UITapGestureRecognizer *)sender {

    if (sender.state == UIGestureRecognizerStateEnded) {
        UIImageView *loadingView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 1024, 768)]; 
        loadingView.image = [UIImage imageNamed:@"Load.png"];
        [self.view addSubview:loadingView];
        [self performSelector:@selector(mainV) withObject:nil afterDelay:2.0];  
    }

}
-(void)loadingView{

        UIImageView *loadingView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 1024, 768)];  
        loadingView.image = [UIImage imageNamed:@"Load.png"];
        [self.view addSubview:loadingView];
        [self performSelector:@selector(mainV) withObject:nil afterDelay:2.0];  

}
-(void)mainV {

        moviePlayer = nil;
        UIStoryboard *sb = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
        UIViewController *vc = [sb instantiateViewControllerWithIdentifier:@"mainViewController"];
        vc.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
        [self presentViewController:vc animated:YES completion:NULL];   
}

非常感谢您的帮助:)

The viewDidLoad方法被调用时viewViewController 的内容已加载到内存中。但到了那个时候，view尚未出现在屏幕上（因此尚未将其添加为subview任何其他的view or window，又名它不在视图层次结构中）。

您应该等待视图出现在屏幕上以呈现您的MovieViewController。 将您的代码移至viewDidAppear:方法而不是viewDidLoad你应该没事。