根据子视图的内容大小调整滚动视图

Question

I'm trying to allow the scroll view to adjust size depending on the size of a subview on this page. All of the other constraints for the objects in the picture work fine.

When I add constraints to my subview to hug to the left, right, and bottom of the screen (and the top of the subview hugs to the bottom of the segmented control) and then update frames, it makes the height of the subview 0.

I can't add a height constraint to the subview because the size of the subview will change dynamically depending on the amount of content in it, which will then change the size of the scroll view.

How can I accomplish this without adding a height constraint?

Answer 1

Your view hierarchy should look like :

Create a single child view of the UIScrollView where we will put all of our content

The content view has to be an explicit size (or a placeholder size in interface builder and set at run time). In other words your content view cannot depend on the scroll view to get its size. It can, however, depend on views outside of the scroll view to get its size.

From Apple Technical Note TN2154

• Set translatesAutoresizingMaskIntoConstraints to NO on all views involved.

• Position and size your scroll view with constraints external to the scroll view.

• Use constraints to lay out the subviews within the scroll view, being sure that the constraints tie to all four edges of the scroll view and do not rely on the scroll view to get their size.

  UIScrollView And Autolayout

  Using UIScrollView with Auto Layout in iOS

Answer 2

Try giving the Equl Heights & Equal Width constraints to your Subview.