Adjust UIScrollView's contentSize with an embedded UIView? - ios

Question

I have a UIScroll view which contains only one subview. The subview called contentViewis an UIView. Here is what I did in viewDidLoad():
self.scrollView = UIScrollView()
self.view.addSubview(self.scrollView)
self.scrollView.backgroundColor = UIColor.yellowColor()
// pin all edges to the edges of the superview (self.view)
self.scrollView.snp_makeConstraints { (make) -> Void in
make.edges.equalTo(self.view)
}
// create contentView
self.contentView = UIView()
self.contentView.backgroundColor = UIColor.redColor()
self.scrollView.addSubview(self.contentView)
// pin the edges of the contentView to the scrollView
self.contentView.snp_makeConstraints { (make) -> Void in
make.edges.equalTo(self.scrollView)
}
let myView = UIView(frame: CGRectMake(100, 100, 20, 300))
myView.backgroundColor = UIColor.greenColor()
self.contentView.addSubview(myView)
The result is this:
There is ne red contentView as shown in the previous screen shot.
Next, I tried to adjust the size of the contenView in viewDidLayoutSubviews():
let newSize: CGSize = self.contentView.systemLayoutSizeFittingSize(UILayoutFittingCompressedSize)
println("newSize: \(newSize)")
The result is:
newSize: (0.0, 0.0)
How can I either setup the correct size of the contentView or set the correct size of the UIScrollView's contentSize?

Answer 1

have you tried setting the var contentSize: CGSize of the UIScrollView? The documentation says
Discussion The unit of size is points. The default size is CGSizeZero.
If you don't know the size of the content view, then I would recommend setting
scrollView.autoresizingMask = (UIViewAutoresizingFlexibleWidth| UIViewAutoresizingFlexibleHeight);
and
scrollView.autoresizesSubviews = YES;
for good measure.