It seems like in a LazyStack, every child needs to be some sort of fixed size or a purely SwiftUI view to work. As soon as I add a UIViewRepresentable of variable height, it starts to stutter again. Our example here in grey stretches down and lists all 99 elements the VStack contains, while the top in black lists just what’s loaded in the LazyVStack. If I add fixedSize(horizontal: false, vertical: true) to the Text element it seems to stop stuttering. When capturing a snapshot of this hierarchy, for both the lazily and normally loaded VStacks, we’re in the exact same application state except, one is providing much more information. I ripped everything out in my view and built it back up one by one - the LazyVStack begins to stutter as soon as I put a VStack/HStack/ZStack around a simple Text element. In the video below, notice the behavior of the scrollbar and the stuttering when we get to the bottom: This is still happening in iOS 15, Version 13.0 beta (13A5155e). Note: Stutter only happens at the top of the scroll view I'm wondering if anyone else has encountered this? Is this a bug in SwiftUI? I've reliably reproduced this for months across different projects and end up resorting to not using Lazy stacks which I wish I could. LazyStacks In SwiftUI (SwiftUI LazyHStack, SwiftUI LazyVStack, LazyStacks For Beginners)In this video, we're going to look at lazystacks in SwiftUI. With LazyVStack, in this example, we can scroll vertically by dragging anywhere on the. Unfortunately it’s only available in iOS 14. WWDC2020 offered a new suite of Views, one interesting one is LazyVStack which allow us to delay the initialization of some content only when needed. the functionality when using an Array versus when using CoreData. Conditionally use VStack in iOS 13 or LazyVStack in iOS 14. With iOS 14, Apple gives you the ability to use lazy stacks. My theory is that due to using a Lazy stack, when a view goes off the screen it gets removed from the view hierarchy, creating a stutter. See that LazyVStack has flexible width and it covers all the screen whereas VStack fits in its context. List with ScrollView and ForEach (4:09) LazyVStack (4:50) Lesson 9: SwiftUI Picker. Get better scroll performance by using LazyHStack and LazyVStack instead of HStack and VStack. Observed behavior: It stops and jitters when it reaches the edge, but doesn't bounce We still have the ability to adjust the horizontal adjustment, the spacing and to pass the content in a. Here’s how we can offer either a VStack in iOS 13 and the new shiny LazyVStack in iOS 14: With this quick trick, we now can use MyVStack following the same API as Apple provides us. Scenario 2 - Scroll fast to the edge so that it has to bounce You can easily achieve this by creating your own wrapper. Scenario 1 - Pull the scrollview beyond the bounds (as if you were pulling to refresh)Įxpected behavior: It behaves as expected where the scrollview stays under your finger I like to work with List in my apps as it provides some more functionality than just a ScrollView with a stack of content inside. Add enough content such that the content size of the scroll view exceeds its bounds There is LazyVStack to work with a large amount of content inside a ScrollView and ensure good scrolling performance.ContentView.swift // LazyVStackIssue // Created by Vishwanath. Add a LazyHStack to a horizontal ScrollView or a LazyVStack to a vertical ScrollView LazyVStack not refreshing content size correctly for child list container view in SwiftUI. animation(.easeInOut, value: alignmentProp)ĭevTechieCourse model will also have an extension which will provide sample data to work with along with a function which will return filtered courses by supplied category.I have encountered this every time I have implemented a Lazy stack within a ScrollView: Struct LazyVStackExample5: View private var alignmentProp: HorizontalAlignment =. Because LazyVStack takes entire width provided by the parent, alignment is more apparent. Because all views are built lazily, there are no other views above that one and therefore, there's nothing to focus and I cannot scroll up and I'm stuck. Just like VStack, LazyVStack supports alignment for child views with just a little difference. However, from time to time the LazyVStack scrolls its content in such a way that the panel containing the call to action button is at the top edge of the screen.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |