[swift4.2] iOS中UITextField通过exte

// MARK: -添加自定义清除按钮

extension UITextField {
    ///给UITextField添加一个清除按钮
    func setModifyClearButton() {
        let clearButton = UIButton(type: .custom)
        clearButton.setImage(UIImage(named: "textfield_clear_btn"), for: .normal)
        clearButton.frame = CGRect(x: 0, y: 0, width: 35, height: 35)
        clearButton.contentMode = .scaleAspectFit
        clearButton.addTarget(self, action: #selector(UITextField.clear(sender:)), for: .touchUpInside)
        self.rightView = clearButton
        self.rightViewMode = .whileEditing
    }

    /// 点击清除按钮，清空内容
    @objc func clear(sender: AnyObject) {
        self.text = ""
    }

}