Question

我想在两个UIImageViews相交时想要编写一个方法。我知道如何做的唯一方法是CGRectIntersectsRect。但这仅适用于矩形，但我的图像是圆形。难道没有更好的选择吗？谢谢！

Answer 1

您可以这样做：

CGPoint a = imageViewA.center;
CGPoint b = imageViewB.center;
CGFloat distance = sqrt(pow((b.x - a.x),2) + pow((b.y - a.y),2));

if(distance < (imageViewA.bounds.size.width/2.0 + imageViewB.bounds.size.width/2.0)){
    //images are touching.
}

Answer 2

假设你知道每个圆的半径（如果图像是一个正方形的大小，那么它将是height/2或width/2如果圆完全占据填充图像）执行以下操作来检测碰撞在两个圈子之间：

计算两个圆的中心点之间的距离：

distance = sqrt((p1.x - p2.x)^2 + (p1.y - p2.y)^2);
```
p1 - Center point of circle 1
p2 - Center point of circle 2
```
计算两个圆的半径之和：

radiusSum = radius1 + radius2;
如果distance <= radiusSum则发生碰撞

Answer 3

它使用核心动画。

CALayer *subLayer = [CALayer layer];
subLayer.backgroundColor = [UIColor blueColor].CGColor;
subLayer.shadowOffset = CGSizeMake(0, 3);
subLayer.shadowRadius = 100.0;
subLayer.shadowColor = [UIColor blackColor].CGColor;
subLayer.shadowOpacity = 0.8;
subLayer.frame = CGRectMake(30, 30, 128, 192);
subLayer.borderColor = [UIColor blackColor].CGColor;
subLayer.borderWidth = 2.0;
subLayer.cornerRadius = 10.0;
[self.view.layer addSublayer:subLayer];

CALayer *imageLayer = [CALayer layer];
imageLayer.frame = subLayer.bounds;
imageLayer.cornerRadius = 48.0;// Here set you right size, then they looks like a circles
imageLayer.contents = (id)[UIImage imageNamed:@"141.png"].CGImage;
imageLayer.masksToBounds = YES;
[subLayer addSublayer:imageLayer];

CGRect Intersects Rect更好的替代方案

3 个答案: