CODEWITHSUNDEEP
iosswiftscrolluiscrollviewautolayout
Dave
Dave

Reputation: 12206

Swift - UIScrollView Scrolls Partially

My problem is slightly different from other's 'Swift UIScrollView' problems when using auto layout:

Problem: Unlike others, when I run my app, it scrolls. My problem is that the scroll cuts off the bottom 20-30% of the content. I can pull to see the buttons did build and are down there, but when I let it go the scroll snaps back to a false bottom which cuts off my content!!! I've been trying, for days, to fix it to scroll the entire height but it continues to cut off!!

Description of app: I used auto layout to layout 6 buttons and labels. Each button a rectangular image, with a label directly beneath it. (sorry, the site won't let me post pictures!)

I have my views arranged like this: MainView > ScrollView > ContentView > Buttons & Labels

I have my contentView pinned to my ScrollView and my ScrollView pinned to my MainView. My buttons and labels all have constraints that are building correctly, to create a list that looks like:

Rectangular button Label beneath it Spacing Rectangular button Label beneath it Spacing Etc.

Can anyone tell me why I can't scroll the full length of the view?

Upvotes: 1

Views: 3077

Answers (2)

vacawama
vacawama

Reputation: 154513

Your description of how your items are constrained is vague, so I'm going to list all of the constraints you need to make this work. Then you can compare what you have to what you need and adjust accordingly.

  1. Your ScrollView should be pinned on all 4 sides to the MainView. (This isn't absolutely necessary. You can constrain your ScrollView however you want, but make sure it can grow as the device and/or orientation changes).

  2. Your ContentView should be pinned on all 4 sides to the ScrollView with offsets of 0.

  3. Since you want your ScrollView to scroll vertically only, constrain the width of the ContentView to the width of the ScrollView using an Equal Widths constraint. To do this, in the Document Outline view, Control-drag from your ContentView to your ScrollView and select Equal Widths from the pop up.

  4. The height of ContentView will be set by the sum total height of everything in it. In order for this to work, your topmost button needs to be pinned to the top of the ContentView, all of your buttons and labels should be pinned to their nearest neighbors, and the bottommost label should be pinned to the bottom of the ContentView. In addition, all of your buttons and labels should have constraints for their widths and heights. I would suggest setting an explicit width constraint and explicit height constraint for your buttons and centering them horizontally in the ContentView. For your labels, set an explicit height constraint and pin the left and right edges to the ContentView.

If you have these constraints and no other ones, your ContentView will be properly sized.

Upvotes: 7

Shamas S
Shamas S

Reputation: 7549

Using contentView, like you said, usually fixes the issue. So chances are you need to take a second look at your contraints. Maybe try this solution in a clean/new project to see that it works. (it does work). My guess would be that some of your constraints conflict each other.

Otherwise I think it would be a good idea to setContentSize of your scrollView in your viewDidLoad.

Another hack would be to place 2 UI objects with their alphas set to zero on the right top corner and left bottom corner. This would hint scrollView to set its contentSize.

Upvotes: 0

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