CODEWITHSUNDEEP
xamarinxamarin.forms
Yuri S
Yuri S

Reputation: 5370

Xamarin Forms Absolute Layout instead of Relative Layout

Since Jason Smith didn't recommend Relative layout and said that we should use Absolute layout I have a question how can we deal with RelativeToView concept?

Absolute Layout sets proportional coordinates and sizes of the elements within itself relative to itself not to each other as RelativeLayout. What to do if I need some elements to be relative to each other? Creating additional Grids and StackLayouts? I would rather use RelativeLayout then or I am missing something.

Decided to add a simplest example and consider we are talking ONLY about Relative and Absolute layouts, no Stack, no Grid. I have 2 buttons and I want to place them as shown in the picture

enter image description here With absolute layout I could define the position of the top button and say it's height 10% of the screen. Now I could shift the bottom button by saying it starts at 11% of the screen. BUT this will change my top button height. If I want my top button to be it's natural "auto" size I cannot do that. So, how can I put my bottom button under top one if I have no idea how much top button occupies on screen? I know how to do it with Relative but how I can do it with Absolute Layout?

It looks like the solution is nest bunch of layouts https://developer.xamarin.com/guides/xamarin-forms/user-interface/layouts/absolute-layout/ Is that the only way? Is that performance still better than Relative layout?

Upvotes: 2

Views: 903

Answers (1)

David Oliver
David Oliver

Reputation: 2321

By its nature RelativeLayout is powerful and offers layouting options that no other Layout on its own does. But that power comes at a cost in performance. Resolving the constraint dependencies consistently and obtaining a final layout doesn't come cheaply.

The point is not necessarily that RelativeLayout should never be used, rather that often times other Layouts can do the job, and yes, even 2-3 nested Layouts can be more performant than a single equivalent RelativePanel.

Grid in particular is a powerful option with which similar effects can be achieved by astute use of Auto, Star, and/or absolute-sized rows and columns as appropriate, plus RowSpan and ColumnSpan, plus element margins, etc.

To consider your specific example, I don't know of a way to achieve what you want with an AbsoluteLayout, at least without the added complication of attached properties. But it seems like a natural fit for a Grid with RowSpan="Auto" on the first row. From a diagram alone I can't tell exactly what other constraints you're going for.

Upvotes: 1

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