移动UIImageView会移动整个视图

Question

所以我试着让一些积木(叫做障碍物)从屏幕的顶部掉下来。这是可行的，但我的代码也将整个视图向下移动...

ViewController.h：

@interface ViewController : UIViewController{
IBOutlet UIImageView * obstacle;
IBOutlet UIImageView * block;
NSTimer * obstacleTimer;
NSTimer * obMoveTimer;
}
-(void)obTimer;
-(void)moveOb;

ViewController.m：

- (void)obTimer{
UIImageView *cloneImageView = [[UIImageView alloc] initWithImage:obstacle.image];
cloneImageView.frame = CGRectMake(0, -20, obstacle.frame.size.width,     obstacle.frame.size.height);
cloneImageView.alpha = obstacle.alpha;
cloneImageView.layer.opacity = obstacle.layer.opacity;
cloneImageView.clipsToBounds = obstacle.clipsToBounds;
cloneImageView.backgroundColor = obstacle.backgroundColor;
cloneImageView.tintColor = obstacle.tintColor;
cloneImageView.contentMode = obstacle.contentMode;
cloneImageView.highlighted = obstacle.highlighted;
cloneImageView.opaque = obstacle.opaque;
cloneImageView.userInteractionEnabled = obstacle.userInteractionEnabled;
cloneImageView.multipleTouchEnabled = obstacle.multipleTouchEnabled;
cloneImageView.autoresizesSubviews = obstacle.autoresizesSubviews;
cloneImageView.layer.zPosition = obstacle.layer.zPosition+1;
cloneImageView.tag = numOb + 1;
numOb++;
cloneImageView.hidden = NO;
[obstacle.superview addSubview:cloneImageView];
}
- (void)moveOb{
    for (int i = 0; i <= numOb; i++){
        UIImageView *viewToAnimate = (UIImageView *)[obstacle.superview viewWithTag:i];
        viewToAnimate.center = CGPointMake(viewToAnimate.center.x, viewToAnimate.center.y + 1);
    }
}
- (void)viewDidLoad {
    obstacleTimer = [NSTimer scheduledTimerWithTimeInterval:3 target:self         selector:@selector(obTimer) userInfo:nil repeats:YES];
    obMoveTimer = [NSTimer scheduledTimerWithTimeInterval:0.05 target:self     selector:@selector(moveOb) userInfo:nil repeats:YES];
    obstacle.hidden = YES;
    [super viewDidLoad];
}

因此，蓝色的区块正在倒塌，整个景观也是如此。这是一张图片：

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Answer 1

这些标签可能会给您带来问题。默认情况下，UIView的tag为0。那么，当你调用viewWithTag的时候，你确定你得到了你想要的obstacle吗？

我曾经多次使用标签，通常是在同一个视图中使用不同的东西。通常，我会为此使用#define一个TAG_START_宏，并将它们隔开，就像这样

#define TAG_START_OBSTACLE 10000

每次我分配一个标签时，我都会使用

NSInteger tag = indexIWantToUse + TAG_START_OBSTACLE;

为了重新获得索引，

NSInteger index = tag - TAG_START_OBSTACLE;

尽管我必须说，因为我在这里没有看到obstacle的定义，所以我认为有一种比使用obstacle.superview更好的方法来获取容器UIView。也许是UIViewController的view属性?其中的一个容器，或者您可以保存指针的某个IBOutlet？