问将动作添加到按钮中，该按钮通过扩展以快捷方式添加到文本框中。

EN

import UIKit
@IBDesignable class TxtFieldCustom: UITextField {
 @IBInspectable var rightButtonImage: UIImage?
    {
    didSet
    {
        updateRightView()
    }
}
func updateRightView()
    {
        //for right Image
        if let image = rightButtonImage
        {
  let button = UIButton(type: .custom)
            button.setImage(image, for: .normal)
            button.imageEdgeInsets = UIEdgeInsetsMake(0, -16, 0, 0)
            button.frame = CGRect(x: 0, y: 0, width: 29, height: 29)
rightView = button
            rightViewMode = .always

        } else
        {
            rightViewMode = UITextFieldViewMode.never
            rightView = nil
        }
    }