How Can One Build iOS Apps with SwiftUI and What Is It?

Gaurav G.

Jun 14, 2022

App Development

If you have been attempting to learn about the characteristic features of SwiftUI and how it can help you in building apps, this is your destination!

In order to get started, it is first necessary to know what SwiftUI is. So, what is SwiftUI?

When it comes to adapting to the new approach that builds apps and declares user interfaces for different Apple platforms like iOS, macOS, and watchOS, SwiftUI developers are going to be a saviour.

The declarative method adopted in the case of SwiftUI app development ensures that you will be able to declare what the purpose of your user interface is. In turn, you can enjoy complete access control over layouts and views, which will make your job of declaration easier.As a UI framework that offers the facility of cross-platform functioning across iOS, tvOS, watchOS, and macOS, SwiftUI is a possession of Apple. What is meant by this is that in order to use your code on platforms owned by Apple, all you need to do is learn how to use the programming language Swift.

To help you understand better, let’s take the example of a “Hi, everyone” programme on SwiftUI developer. Such a code sample will be created by Xcode upon creating a SwiftUI app.

What are the views on SwiftUI app development?

When one first opens an app, what does the user find? It is the pictures, animations, texts, and a lot of other elements. As an essential component of the user interface, views in SwiftUI play a crucial role in the development process.

When using SwiftUI, you must know that it is essential that you have a property if you wish to use View.

Below is provided a code sample with help from a body that we already have. What we shall look into is the return on some investments.

var body : some View

This example resonates with the “Hi, everyone” code mentioned in the previous lines.

What are the controls in SwiftUI?

As far as user interaction in the SwiftUI apps is concerned, controls play a significant role. Control in SwiftUI development includes everything from response to gestures by users to clicking on a button.

In fact, SwiftUI even allows you to craft some unique elements of interaction for users with the help of controls. Its operation across multiple Apple platforms helps build interfaces for varied users.

Consider the example of the UI Button control that ensures user interactions through the clicking of a button. Have a look at the syntax below.

@MainActor class UIButton : UIControl

What is Referred to as the layout structure in SwiftUI Development?

When it comes to laying out views on the user interface of one’s apps, SwiftUI developers help by providing support. What enables the laying out of these views is the usage of stacks such as HStack, VStack, and ZStack. These stacks are often referred to as the "children of the container." Much like the parent elements in HTML, the container in SwiftUI is known to help in the case of laying out app structures.

To understand the functioning of SwiftUI developers better, let’s try to grasp what stacks in a layout structure actually are.

HStack, or Horizontal Stack in SwiftUI

An app layout with horizontal arrangements is no longer an impossible task to achieve. HStack enables its users to display all the views at once. In order to help you understand the functioning of HStack in horizontal arrangements better, here is an example:

VStack, or Vertical Stack in SwiftUI

With the aid of VStack, SwiftUI app development offers vertical arrangements. The children in the views can be easily stacked in vertical patterns. The example below illustrates how to use the VStack tool for vertical stacking.

import SwiftUIstruct ContentView : View {var body: some View {VStack {Text("Introducing").font(.title)Text("A Demo App")}}}

ZStack

As the third and most diverse of the stacks offered by SwiftUI developers, ZStack offers the facility of stacking the children on top of each other. Furthermore, it allows users to align stacks in both the x and y axes.case of default, it alligns each child to the central position. Refer to the illustration below to understand the functioning of ZStack better.

@frozen struct ZStack<Content> where Content : View

As is evident, ZStack arranges each child on a higher z axis value as compared to the previous child. This feature can be used to stack various items, such as texts and images.

The example underneath explains how one can make use of ZStack to stack the image of a car over an HStack containing text, keeping the alignment to the top to offer good readability. This ensures that the image and the text do not overlap with each other.

How to build an app with a SwiftUI developer?

SwiftUI app development needs you to amalgamate the techniques described above. So, let’s get started with our attempt at building a SwiftUI app that will in turn help build mobile apps with the help of the technologies offered by the platform. ContentView.swift should contain the entire code.Let’s begin by launching Xcode, upon which we will click on "Create a new Xcode project."As the next step, we select the App and proceed by clicking on Next.The field Product Name asks you to type “demoapp” and click on Next. Xcode will launch the project on its own at some point.It is time now to locate ContentView.swift, and this is the file that will contain the SwiftUI code.We shall remove the code except for what is shown below.

Xcode contains a navigator panel from where we need to select the iPhone simulator of our choice and click on the “play” symbol in order to start running the program.

Conclusion: The blog is an introductory tutorial to using Apple’s UI framework called the SwiftUI, a framework essential to building apps across different platforms. Moreover, it offers an insight into the code concepts of SwiftUI app development which includes everything from layout structuring to building apps with the aid of different types of stacks.