动画完成后所有 UIElement 都变得不可访问

我正在尝试通过具有每个灯光坐标的 CGRect 数组来实现城市灯光动画。然后围绕这些 CGRect 创建 UIView。这个逻辑（感谢Darren https://stackoverflow.com/users/1077601/darren用于帮助实现此逻辑）工作正常，但是动画完成后，屏幕上的所有其他元素（UIButtons、Sliders、其他 UIImageViews 等）都将变得无法访问。甚至我的滑动手势也没有响应。在动画之前和期间，所有元素都响应良好，但一旦动画完成，它们都将变得无法访问。我也尝试过[UIView bringSubviewToFront:]将一些元素放在前面，看看这是否有助于使它们易于访问，但没有帮助。我认为这不是问题，因为即使我尝试通过将灯光发送到背景来创建灯光视图[self.view sendSubviewToBack:light];动画完成后，一切都变得无法访问。

如果有人可以帮助/建议我我缺少什么，我将不胜感激。

这是我的代码逻辑和城市灯光动画的相应场景。 rects 和 lits 是 ivars。

- (void)viewDidLoad {
    pageCount=5;
    AVAudioSession * audioSession = [AVAudioSession sharedInstance];
    //Setup the audio session
    //...
    pageNum=1;
    //put imageviews in place
    //...
    //load a page
    [self loadPage];
    [self loadAudio];

    [self cityLightsSetUp];
    [super viewDidLoad];
}


-(void)loadPage{
    //Logic to load page...    
    /...
    if (pageNum == 3){
      [self startCityLights];
    }
}


- (void)cityLightsSetUp
{
    rects = [[NSMutableArray alloc] init];
    lit = [[NSMutableArray alloc] init];
    [rects addObject:[NSValue valueWithCGRect:CGRectMake(58, 217, 10, 10)]];
    [rects addObject:[NSValue valueWithCGRect:CGRectMake(71, 217, 10, 10)]];
    [rects addObject:[NSValue valueWithCGRect:CGRectMake(84, 217, 10, 10)]];
    [rects addObject:[NSValue valueWithCGRect:CGRectMake(97, 217, 10, 10)]];

    [rects addObject:[NSValue valueWithCGRect:CGRectMake(58, 231, 10, 10)]];
    [rects addObject:[NSValue valueWithCGRect:CGRectMake(71, 231, 10, 10)]];
    [rects addObject:[NSValue valueWithCGRect:CGRectMake(84, 231, 10, 10)]];
    [rects addObject:[NSValue valueWithCGRect:CGRectMake(97, 231, 10, 10)]];

    [rects addObject:[NSValue valueWithCGRect:CGRectMake(58, 245, 10, 10)]];
    [rects addObject:[NSValue valueWithCGRect:CGRectMake(71, 245, 10, 10)]];
    [rects addObject:[NSValue valueWithCGRect:CGRectMake(84, 245, 10, 10)]];
    [rects addObject:[NSValue valueWithCGRect:CGRectMake(97, 245, 10, 10)]];

    [rects addObject:[NSValue valueWithCGRect:CGRectMake(58, 258, 10, 10)]];
    [rects addObject:[NSValue valueWithCGRect:CGRectMake(71, 258, 10, 10)]];
}

- (void)startCityLights
{
    [self lightRandomLight];
    [self performSelector:@selector(switchOffRandomLight) withObject:nil afterDelay:1.0];
}

- (void)lightRandomLight
{
    BOOL escape = NO;
    int rand;

    while (!escape) {
        BOOL alreadyLit = NO;
        rand = arc4random() % [rects count];
        // Check if already lit
        for (UIView *view in lit) {
            CGRect litRect = view.frame;
            CGRect ranRect = [[rects objectAtIndex:rand] CGRectValue];
            if (CGRectContainsRect(litRect, ranRect)) {
                alreadyLit = YES;
            }
        }

        if (!alreadyLit) {
            UIView *light = [[UIView alloc] initWithFrame:[[rects objectAtIndex:rand] CGRectValue]];
            light.backgroundColor = [UIColor orangeColor];
            [lit addObject:light];
            [self.view addSubview:light];
            //[self.view sendSubviewToBack:light];
            escape = YES;
        }
    }

    [self performSelector:@selector(lightRandomLight) withObject:nil afterDelay:0.2];
}

- (void)switchOffRandomLight
{
     NSLog(@"switchOffRandomLight");
    int rand = arc4random() % [lit count];
    UIView *light = [lit objectAtIndex:rand];
    [lit removeObject:light];
    [light removeFromSuperview];

    [self performSelector:@selector(switchOffRandomLight) withObject:nil afterDelay:0.5];
}

看起来，一旦所有灯都亮起，while 循环就会连续运行，尝试获取未亮起的随机数。这就是阻塞主线程的原因。

您所需要的只是在方法开始时检查所有灯是否都亮起，如果没有则继续。

在 lightRandomLight 方法的底部，替换

[self performSelector:@selector(lightRandomLight) withObject:nil afterDelay:0.2];

with

if ([lit count] != [rects count]) {
    [self performSelector:@selector(lightRandomLight) withObject:nil afterDelay:0.2];
} else {
    [NSObject cancelPreviousPerformRequestsWithTarget:self];
}

当所有灯都亮起时它就会停止。