ios - UIScrollView 按钮点击不起作用

Question

我将 UIButtons 排列在水平 UIScrollView 中。我已将 contentView UIView 添加到 UIScrollView 中，按钮位于其中。 ScrollView 内容宽度比屏幕大小更宽，因此某些按钮一开始就不在屏幕上。当我滚动并将它们拖到屏幕上时，点击它们不会调用它应该的功能。另一方面，点击最初在屏幕上启动的按钮是有效的。希望能帮助您解决问题。

Answer 1

这是一个小例子，如果有帮助的话:

ViewController 类:UIViewController {

    @IBOutlet weak var scrollView: UIScrollView!

    override func viewDidLoad() {
        super.viewDidLoad()

        let button1 = UIButton()
        button1.backgroundColor = UIColor.redColor()
        button1.setTitle("Button 1", forState: .Normal)
        button1.setTranslatesAutoresizingMaskIntoConstraints(false)
        self.scrollView.addSubview(button1)
        self.scrollView.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|-(100)-[button1(100)]", options: NSLayoutFormatOptions(0), metrics: nil, views: ["button1": button1]))
        self.scrollView.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|-[button1(100)]", options: NSLayoutFormatOptions(0), metrics: nil, views: ["button1": button1]))
        button1.addTarget(self, action: "button1", forControlEvents: .TouchUpInside)

        let button2 = UIButton()
        button2.backgroundColor = UIColor.greenColor()
        button2.setTitle("Button 2", forState: .Normal)
        button2.setTranslatesAutoresizingMaskIntoConstraints(false)
        self.scrollView.addSubview(button2)
        self.scrollView.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|-(500)-[button2(100)]-(300)-|", options: NSLayoutFormatOptions(0), metrics: nil, views: ["button2": button2]))
        self.scrollView.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|-[button2(100)]", options: NSLayoutFormatOptions(0), metrics: nil, views: ["button2": button2]))
        button2.addTarget(self, action: "button2", forControlEvents: .TouchUpInside)
    }

    func button1() {
        print("button1")
    }

    func button2() {
        print("button2")
    }
}