Question

我在屏幕上添加了2个UIViews，我想检测它们是否发生碰撞。如果是这样，那么我需要在屏幕上显示警告。

Answer 1

怎么样

if (CGRectIntersectsRect(secondView.frame, sender.frame)) {
        // Do something
    }

Answer 2

您可以通过检查其框架是否相交来检查两个视图是否相交。这是一个例子：

let view1 = UIView(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
let view2 = UIView(frame: CGRect(x: 90, y: 90, width: 50, height: 50))

extension UIView {
    func intersects(_ otherView: UIView) -> Bool {
        if self === otherView { return false }
        return self.frame.intersects(otherView.frame)
    }
}

print(view1.intersects(view2)) // Prints true because the 2 views are intersecting

每次更新任何视图框架（即更改其大小和/或位置）时，您都可以调用intersects(_:)。如果方法返回true，请使用UIAlertController显示提醒。

Answer 3

// The Pan Gesture
func createPanGestureRecognizer(targetView: UIImageView) 
{

    var panGesture = UIPanGestureRecognizer(target: self, action:("handlePanGesture:"))
    targetView.addGestureRecognizer(panGesture)
}

// THE HANDLE

   func handlePanGesture(panGesture: UIPanGestureRecognizer) {


    //        get translation

    var translation = panGesture.translationInView(view)
    panGesture.setTranslation(CGPointZero, inView: view)
    println(translation)


    //create a new Label and give it the parameters of the old one
    var label = panGesture.view as UIImageView
    label.center = CGPoint(x: label.center.x+translation.x, y: label.center.y+translation.y)
    label.multipleTouchEnabled = true
    label.userInteractionEnabled = true

    if panGesture.state == UIGestureRecognizerState.Began {

        //add something you want to happen when the Label Panning has started
    }

    if panGesture.state == UIGestureRecognizerState.Ended {

       //add something you want to happen when the Label Panning has ended

    }


    if panGesture.state == UIGestureRecognizerState.Changed {

    //add something you want to happen when the Label Panning has been change ( during the moving/panning ) 

    }

    else {

       // or something when its not moving
    }

    }

在Swift 3.0中检测两个对象的碰撞？

3 个答案: