swift collectionviewcell 点击高亮

子类uicollectionviewcell，override isHighlighted属性

override var isHighlighted: Bool {
        didSet {
            if isHighlighted {
                label.textColor = .white
                label.backgroundColor = UIColor(hexString: "#999999")
            } else {
                label.textColor = UIColor(hexString: "#999999")
                label.backgroundColor = UIColor(hexString: "#F8F8F8")
            }
        }
    }