剛才加的iOS群分享了一份OC版本的代碼,大概看了一下覺得改成Swift3.0的也很簡單 于是就花幾分鐘動手改了一下。

import UIKit

fileprivate var rectNameKey:(Character?,Character?,Character?,Character?)

extension UIButton
{
    func setEnlargeEdgeWith(top:CGFloat,right:CGFloat,bottom:CGFloat,left:CGFloat)
    {
        objc_setAssociatedObject(self, &rectNameKey.0, top, .OBJC_ASSOCIATION_COPY_NONATOMIC)
        objc_setAssociatedObject(self, &rectNameKey.1, right, .OBJC_ASSOCIATION_COPY_NONATOMIC)
        objc_setAssociatedObject(self, &rectNameKey.2, bottom, .OBJC_ASSOCIATION_COPY_NONATOMIC)
        objc_setAssociatedObject(self, &rectNameKey.3, left, .OBJC_ASSOCIATION_COPY_NONATOMIC)
    }
    
    open override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
        
        if let topEdge = objc_getAssociatedObject(self, &rectNameKey.0) as? CGFloat,
            let rightEdge = objc_getAssociatedObject(self, &rectNameKey.1) as? CGFloat,
            let bottomEdge = objc_getAssociatedObject(self, &rectNameKey.2) as? CGFloat,
            let leftEdge = objc_getAssociatedObject(self, &rectNameKey.3) as? CGFloat
        {
            return CGRect(x: bounds.origin.x - leftEdge, y: bounds.origin.y - topEdge, width: bounds.width + leftEdge + rightEdge, height: bounds.height + topEdge + bottomEdge).contains(point) ? self : nil
        }
        return super.hitTest(point, with: event)
    }
}

即拿即用。