如何获取动画UIImageView的坐标

Question

因此，我有一个UIImageView，它具有动画UIImage。 UIImageView本身使用CAKeyframeAnimation和CGMutablePathRef来动画，以在路径中提供一些随机性。我的问题是我需要跟踪何时点击动画的UIIMageView。

我已经把头撞在墙上了一会儿，看起来我应该将UITouch与UIImage的表现层在屏幕上的位置进行比较，但我无法弄清楚如何获取它的坐标。

所以主要的问题是，我如何获得UIIMageView的坐标，并在屏幕上进行动画并将其与龙头的出现位置进行比较？

如果我运行的代码是正确的，现在，它会抛出一个错误：

- [CALayer的中心]：无法识别的选择发送到实例0xa105150

它不再崩溃，但我仍然在对于如何确定UIImageView在屏幕上移动时的位置有所损失。

我的相关代码如下。任何帮助将不胜感激。

- (void)animateCarrierFish 
{ 
    NSInteger getWhichFish = (arc4random()%[self.fishes count]); 
    NSArray *selectedFish = [NSArray arrayWithArray:[self.fishes objectAtIndex:getWhichFish]]; 
    UIImage *fishName = [selectedFish objectAtIndex:0]; 

    UIImageView *fishCarrier = [[UIImageView alloc] initWithImage:fishName]; 
    fishCarrier.animationImages = selectedFish; 
    fishCarrier.animationDuration = 1.5; 
    fishCarrier.animationRepeatCount = 0; 
    fishCarrier.frame = CGRectMake(0, 0, fishName.size.width*screenScale, fishName.size.height*screenScale); 

    NSInteger startPoint; 
    NSInteger endPoint; 
    NSInteger oppositeMod; 

    NSInteger fromWhichDirection = (arc4random()%2); 
    if(fromWhichDirection==1) 
    { 
     startPoint = rightEdge; 
     endPoint = leftEdge; 
     oppositeMod = -rightEdge; 
     fishCarrier.transform = CGAffineTransformMakeScale(-1, 1); 
    } else { 
     startPoint = leftEdge; 
     endPoint = rightEdge; 
     oppositeMod = 0; 
    } 

    NSInteger aniSpeed = [self getRandomNumberBetweenMin:15 andMax:20]; 

    CAKeyframeAnimation *pathAnimation = [CAKeyframeAnimation animationWithKeyPath:@"position"]; 
    pathAnimation.duration = aniSpeed; 
    pathAnimation.calculationMode = kCAAnimationCubic; 
    pathAnimation.fillMode = kCAFillModeForwards; 
    pathAnimation.removedOnCompletion = NO; 

    CGMutablePathRef pointPath = CGPathCreateMutable(); 

    NSInteger yPoint = [self getRandomNumberBetweenMin:waterLine andMax:seaFloor]; 
    CGPathMoveToPoint(pointPath, NULL, startPoint, yPoint); 

    NSInteger howManyDips = [self getRandomNumberBetweenMin:2 andMax:4]; 

    int i=0; 
    for (i = 0; i < howManyDips; i++) 
    { 
     yPoint = [self getRandomNumberBetweenMin:waterLine andMax:seaFloor]; 
     NSInteger xMod = [self getRandomNumberBetweenMin:-25 andMax:25]; 

     NSInteger xPoint = (([[UIScreen mainScreen] bounds].size.height/(howManyDips+1))*(i+1)) + xMod + oppositeMod; 
     if (xPoint <0) 
     { 
      xPoint = xPoint*-1; 
     } 
     CGPathAddLineToPoint(pointPath, NULL, xPoint, yPoint); 
    } 

    yPoint = [self getRandomNumberBetweenMin:waterLine andMax:seaFloor]; 
    CGPathAddLineToPoint(pointPath, NULL, endPoint, yPoint); 
    pathAnimation.path = pointPath; 
    CGPathRelease(pointPath); 


    [fishCarrier.layer addAnimation:pathAnimation forKey:@"pathAnimation"]; 
    [self.view addSubview:fishCarrier]; 
    [fishCarrier startAnimating]; 

    fishCarrier.userInteractionEnabled = YES; // these two lines don't seem to do anything 
    fishCarrier.multipleTouchEnabled = YES; 
    fishCarrier.tag=[self.swimmers count]; 

    [self.swimmers addObject:fishCarrier]; 
} 

- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event 
{ 
    [super touchesBegan:touches withEvent:event]; 

    UITouch *touch = [touches anyObject]; 
    CGPoint touch_point = [touch locationInView:self.view]; 


    for (UIImageView *image in self.swimmers) { 
     // HOW do I get the coordinates in the main view of this sublayer? 
    } 
} 

Answer 1

我能够最终得到的对象报告，他们使用了如下修改我的touchesBegan方法是在屏幕上：

- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event 
{ 
    [super touchesBegan:touches withEvent:event]; 

    UITouch *touch = [touches anyObject]; 
    CGPoint startPoint = [touch locationInView:self.view]; 
    CGFloat x = startPoint.x; 
    CGFloat y = startPoint.y; 

    //create touch point 
    CGPoint touchPoint = CGPointMake(x, y); 

    // loop through the items we're iterested in being tapped on here 
    for (UIImageView *fish in self.swimmers) { 
     CGRect fishFrame = [[fish.layer presentationLayer] frame]; 

     if (CGRectContainsPoint(fishFrame, touchPoint)) { 
      NSLog(@"You hit fish: %u",fish.tag); // do stuff here 
     } 
    } 
} 

Answer 2

你为什么想到CALayer向center消息作出响应？如果您已阅读其documentation，则会发现它没有实施名为center的方法。如果你想获得该层的几何中心，手动计算的话：

CGPoint center; 
center.x = CGRectGetMidX(layer.bounds); 
center.y = CGRectGetMidY(layer.bounds); 

编辑：看来你要相对于超级中锋（层查看什么...？）：

CGPoint center; 
center.x = CGRectGetMidX(layer.frame); 
center.y = CGRectGetMidY(layer.frame);