Book Image

SwiftUI Cookbook - Second Edition

By : Giordano Scalzo, Edgar Nzokwe
Book Image

SwiftUI Cookbook - Second Edition

By: Giordano Scalzo, Edgar Nzokwe

Overview of this book

SwiftUI provides an innovative and simple way to build beautiful user interfaces (UIs) for all Apple platforms, from iOS and macOS through to watchOS and tvOS, using the Swift programming language. In this recipe-based cookbook, you’ll cover the foundations of SwiftUI as well as the new SwiftUI 3 features introduced in iOS 15 and explore a range of essential techniques and concepts that will help you through the development process. The cookbook begins by explaining how to use basic SwiftUI components. Once you’ve learned the core concepts of UI development, such as Views, Controls, Lists, and ScrollViews, using practical implementations in Swift, you'll advance to adding useful features to SwiftUI using drawings, built-in shapes, animations, and transitions. You’ll understand how to integrate SwiftUI with exciting new components in the Apple development ecosystem, such as Combine for managing events and Core Data for managing app data. Finally, you’ll write iOS, macOS, and watchOS apps by sharing the same SwiftUI codebase. By the end of this SwiftUI book, you'll have discovered a range of simple, direct solutions to common problems encountered when building SwiftUI apps.
Table of Contents (17 chapters)

Displaying tabular content with LazyHGrid and LazyVGrid

Like lazy stacks, lazy grids also use lazy loading to display a collection of items. They only initialize only subset of items that will soon be displayed on the screen when the user scrolls. You can display content from top to bottom using a LazyVGrid view and from left to right using a LazyHGrid view.

In this recipe, we'll use the LazyVGrid and LazyHGrid views to display an extensive range of numbers embedded in colorful circles.

Getting ready

Create a new SwiftUI app called LazyGrids.

How to do it…

We'll use a ForEach structure count for numbers from 0 to 999 and display them in a LazyHGrid, then repeat similar steps to display the numbers in a LazyVGrid view. The steps are as follows:

  1. In the ContentView struct, just above the body variable, create an array of GridItem columns. The GridItem struct helps configure the layout of the lazy grid:
        let columnSpec = [
    ...