UIScrollView不显示动态添加的内容

Question

I need some help with the UIScrollView. I am loading content in this:

for i in _start ..< _loopPages {

        let articleController = createViewController(index: i)
        viewControllers.append(articleController)
        articleController.didMoveToParentViewController(self)
        scrollView.addSubview(articleController.view)
        articleController.view.setNeedsDisplay()
    }

and this is the function that calculates the size of the view:

func calculateScrollViewSize(){
for i in _start ..< numberOfArticles {
        let articleController = viewControllers[i]
        articleController.view.frame = view.bounds
        let x = i * Int(articleController.view.bounds.size.width)
        print("RECT: ", CGRect(origin: CGPoint(x: x, y: 0), size: view.bounds.size))
        articleController.view.frame = CGRect(origin: CGPoint(x: x, y: 0), size: view.bounds.size)
    }

    let contentWidth = CGFloat(numberOfArticles) * view.bounds.size.width
    let contentHeight = view.bounds.size.height
    scrollView.contentSize = CGSize(width: contentWidth, height: contentHeight)

    let offsetX = currentPage * Int(view.bounds.size.width)
    let offsetY = 0
    scrollView.contentOffset = CGPoint(x: offsetX, y: offsetY)
    //scrollView.contentInset.top = 0

    scrollView.setNeedsDisplay()
}

The first 10 views are loaded and displayed as they should, but when I load the next 10 views all I get is white space. If I change the screen orientation the pages are displayed, but if I don't all I get is white screens. I can scroll through the screens, the size of the scrollview is updated but the content is not displayed. When the user scrolls to page 10 the next 10 are being loaded. Can any of you tell me what am I doing wrong here.

Answer 1

My problem was that the dynamically added views had size of zero, so after i set the size of the viewController (the one created in the createViewController(index: i) method) to be the size of the screen, everything worked like a charm.

Hope it helps somebody someday.