自定义button的init方法

class WBButton: UIButton {

    convenienceinit(text: String , fontSize:CGFloat , normalColor: UIColor , highlightedColor: UIColor , backgroundImageName: String) {

        self.init()

        self.setTitle(text, for: .normal)

        self.titleLabel?.font =UIFont.boldSystemFont(ofSize: fontSize)

        self.setTitleColor(normalColor, for: .normal)

        self.setTitleColor(highlightedColor, for: .highlighted)

        self.setBackgroundImage(UIImage(named: backgroundImageName), for: .normal)

    }

}