Question

 func setupScrollView(){
        let scrollWidth = scrollView.frame.size.width
        let scrollHeight = scrollView.frame.size.height

        scrollView.isPagingEnabled = true

        var contentWidth : CGFloat = 0.0

        for x in 0...bannerImages.count - 1 {

            let image = (UIImage(named: bannerImages[x]))
            let imageView = UIImageView(image: image)
            imageView.clipsToBounds = true

            var newX : CGFloat = 0.0
            newX = scrollWidth / 2 + scrollWidth * CGFloat(x)
            contentWidth += newX
            scrollView.addSubview(imageView)
            imageView.frame = CGRect(x: newX - itemWidth / 2, y: scrollView.frame.midY - itemWidth / 2, width: itemWidth, height: itemWidth)

        }

        scrollView.contentSize = CGSize(width:contentWidth, height: scrollHeight)

    }

我在viewDidAppear中有这个，我没有自动播放。

我的内容大小宽度增加了不应该存在的大量空间。我有3个图像我正在显示，我可以滚过第3个图像，再次分页2次。

有什么想法吗？

Answer 1

我不确定你想要完成什么，但我认为你的数学已经完成了。如果您尝试在滚动视图中的x轴上堆叠三个图像并将滚动视图内容大小设置为图像宽度的总和，那么计算您的newX，如newX = itemWidth * CGFloat(x)也设置图像框架imageView.frame = CGRect(x: newX, y: scrollView.frame.midY - itemWidth / 2, width: itemWidth, height: itemWidth) 。

我认为这不是实施ScrollView的正确方法！可能不是最佳做法。我认为您应该在child view中调用ScrollView contentView，然后为该视图设置适当的AutoLayout Constraints。之后，将每个图像添加到contentView。这样事情会更容易。

查看此博文https://www.natashatherobot.com/ios-autolayout-scrollview/

Answer 2

我更新此代码检查评论....

    func setupScrollView(){
        let scrollWidth = scrollView.frame.size.width
        let scrollHeight = scrollView.frame.size.height

        scrollView.isPagingEnabled = true

        var contentWidth : CGFloat = 0.0

        for x in 0...bannerImages.count - 1 {

            let imageView = UIImageView(image: bannerImages[x])
            imageView.clipsToBounds = true

            var newX : CGFloat = 0.0
            newX = scrollWidth / 2 + scrollWidth * CGFloat(x)
//            contentWidth += newX
            // This is wrong here. Because you already add scrollview widht in newx and by this line you are adding it again.
            contentWidth = newX
            scrollView.addSubview(imageView)
            imageView.frame = CGRect(x: newX - itemWidth / 2, y: scrollView.frame.midY - itemWidth / 2, width: itemWidth, height: itemWidth)

        }
        contentWidth = contentWidth + (itemWidth / 2)
        // Add this line also beacuse newx store half width so you have to add extra half space in content width
        scrollView.contentSize = CGSize(width:contentWidth, height: scrollHeight)

    }

计算UIScrollView的内容大小

2 个答案: