ios - 快速点击 UIButton 没有响应

Question

    addButton = UIButton(type: .custom)
    addButton.setTitle("add", for: .normal)
    addButton.setTitle("tapped", for: .highlighted)
    addButton.titleLabel?.font = UIFont.systemFont(ofSize: 12)
    addButton.backgroundColor = UIColor.lightGray
    addButton.translatesAutoresizingMaskIntoConstraints = false
    addButton.addTarget(self, action: #selector(dosome(_:)), for: .touchUpInside)
    let bottom_button: NSLayoutConstraint = NSLayoutConstraint(item: addButton, attribute: NSLayoutAttribute.bottom, relatedBy:NSLayoutRelation.equal, toItem:mainView, attribute:NSLayoutAttribute.bottom, multiplier:1.0, constant: -10)
    let right_button: NSLayoutConstraint = NSLayoutConstraint(item: addButton, attribute: NSLayoutAttribute.right, relatedBy:NSLayoutRelation.equal, toItem:mainView, attribute:NSLayoutAttribute.right, multiplier:1.0, constant: -20)
    let height_button: NSLayoutConstraint = NSLayoutConstraint(item: addButton, attribute: NSLayoutAttribute.height, relatedBy:NSLayoutRelation.equal, toItem:nil, attribute:.notAnAttribute, multiplier:1.0, constant: 20)
    let width_button: NSLayoutConstraint = NSLayoutConstraint(item: addButton, attribute: NSLayoutAttribute.width, relatedBy:NSLayoutRelation.equal, toItem:nil, attribute:.notAnAttribute, multiplier:1.0, constant: 35)
    addButton.addConstraint(height_button)
    addButton.addConstraint(width_button)
    mainView.addSubview(addButton)
    mainView.addConstraint(bottom_button)
    mainView.addConstraint(right_button)

@IBAction func dosome(_ sender: UIButton) {
    print("tttttt")
}

点击后，按钮的文本将变为突出显示的标题，而无需执行任何操作。谁能指出哪里出了问题吗？

Answer 1

使用addButton.isHighlighted = false它会起作用。