SwiftUI: Center Content in ScrollView

Question

I'm trying to center a bunch of views in a VStack within a ScrollView in SwiftUI. To simplify things, I'm just trying to get it to work with a single Text view. Here's what I've come up with so far:

var body: some View {
  ScrollView(alwaysBounceVertical: true){
    HStack(alignment: .center) {
      Spacer()
      Text("This Is a Test")
      Spacer()
    } //HStack
    .background(Color.green)
  } //ScrollView
  .background(Color.gray)
}

This results in this:

I want the text to be in the middle like this:

So the HStack should be full-width and the Text should be centered within it. It seems like this should be easy, but I don't get what I'm doing wrong. :)

I'm using Xcode beta 5 and your code is working fine with me. Which Xcode are you using ? Because In beta 5, ScrollView doesn't have alwaysBounceVertical Modifier. — Anjali Kevadiya
– Anjali Kevadiya, Commented Oct 1, 2019 at 15:52

Benjamin Kindle · Accepted Answer · 2019-06-15 01:28:22Z

21

Using GeometryReader, you can get information about the size of the containing view and use that to size your view.

    var body: some View {
        GeometryReader { geometry in                <--- Added
            ScrollView(alwaysBounceVertical: true){
                HStack(alignment: .center) {
                    Spacer()
                    Text("This Is a Test")
                    Spacer()
                } //HStack
                .frame(width: geometry.size.width)  <--- Added
                .background(Color.green)
            } //ScrollView
        .background(Color.gray)
    }
}

edit: after looking into this more, it seems that part of the problem is that you are using a ScrollView. If you remove that parent, the spacers in the HStack will automatically cause stretching to fill the view. I'm guessing the automatic stretching doesn't happen in ScrollViews because there's no finite limit to how big it can be, how much would it stretch? (because a ScrollView can scroll in any direction)

edited Jun 15, 2019 at 1:28

answered Jun 15, 2019 at 1:20

Benjamin Kindle

1,84415 silver badges25 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

p0fi Over a year ago

This sounds like a good explanation. But should it not be possible maybe to limit one scrolling direction for a scrollview to fix such issues? 🤔

M Reza · Accepted Answer · 2019-06-15 05:43:41Z

4

This seems to be a bug in Xcode 11.0 beta, ScrollView content wouldn't fill the scroll view. If you replace the ScrollView with a List it will work as expected. But if you have to use a scroll view, one workaround is to fix the scroll view's content width.

So your code will look something like this:

ScrollView(alwaysBounceVertical: true) {
  HStack(alignment: .center) {
    Spacer()
    Text("This Is a Test")
    Spacer()
  } // HStack
  .frame(width: UIScreen.main.bounds.width) // set a fixed width
  .background(Color.green)
} // ScrollView
.background(Color.gray)

Result:

edited Jun 15, 2019 at 5:43

answered Jun 15, 2019 at 5:34

M Reza

20k15 gold badges72 silver badges78 bronze badges

3 Comments

Matteo Pacini Over a year ago

Please use GeometryReader rather the UIScreen bounds

Clifton Labrum Over a year ago

@MatteoPacini Why is that? Is it because it won't work when the device is rotated?

Clifton Labrum Over a year ago

This solution works, but now I'm just debating between setting the .frame and using GeometryReady. Thank you!

Danilo · Accepted Answer · 2021-05-17 22:02:11Z

4

You should use the modifier frame and set its maxWidth: .infinity. So it tells its parent: "the wider, the better" :)

var body: some View {
  ScrollView(.vertical, showsIndicators: true){
    HStack(alignment: .center) {
      Spacer()
      Text("This Is a Test")
        .frame(maxWidth: .infinity) // <- this
      Spacer()
    } //HStack
    .background(Color.green)
  } //ScrollView
  .background(Color.gray)
}

And this works regardless its parent. Scrollview or whatever View it's set in.

Paul is doing a great job clarifying it to all of us here:

https://www.hackingwithswift.com/quick-start/swiftui/how-to-give-a-view-a-custom-frame

Answer compatible with Xcode 12.1 (12A7403) I hope this helps 👍 dsa

edited May 17, 2021 at 22:02

answered Nov 10, 2020 at 12:04

Danilo

594 bronze badges

2 Comments

Erkam KUCET Over a year ago

There isn't constructor method with alwaysBounceVertical for ScrollView.

Danilo Over a year ago

@ErkamKUCET fixed

Josh Brown · Accepted Answer · 2024-05-09 14:44:12Z

3

Depending on what you're doing, ViewThatFits might be a good solution for this. For my use case, I needed a horizontal ScrollView if the content was too wide, but an HStack was sufficient otherwise.

This works for me:

var body: some View {
  ViewThatFits {
    HStack(alignment: .center) {
      Spacer()
      Text("This Is a Test")
      Spacer()
    } //HStack
    .background(Color.green)

    ScrollView(alwaysBounceVertical: true){
      HStack(alignment: .center) {
        Spacer()
        Text("This Is a Test")
        Spacer()
      } //HStack
      .background(Color.green)
    } //ScrollView
    .background(Color.gray)
  }
}

answered May 9, 2024 at 14:44

Josh Brown

53.4k11 gold badges58 silver badges84 bronze badges

Collectives™ on Stack Overflow

SwiftUI: Center Content in ScrollView

4 Answers 4

1 Comment

3 Comments

2 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

1 Comment

3 Comments

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related