SwiftUI Image Picker Implementation Made Easy

If you’re developing a SwiftUI app and need to access and manage the photo library, the SwiftUI Image Picker is a highly useful tool. It allows users to select and interact with photos in an intuitive manner.

In this blog, we’ll dive deep into how you can implement and customize a photos picker, optimize memory usage, and manage data effectively. From setting up the picker to handling selected images, we’ll cover it all with practical examples.

What is a SwiftUI Image Picker?

The SwiftUI Image Picker simplifies the task of accessing the photo library by providing a user-friendly interface for selecting images. Whether you need to select multiple photos or focus on a single image, the image picker streamlines the entire process. This functionality is particularly useful when your app involves displaying user-selected content, uploading photos, or creating customized galleries.

Setting Up the Basics: Importing Necessary Frameworks

To get started, you need to import the required frameworks. Use the following code to bring in SwiftUI and PhotosUI, which powers the photos picker functionality.

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1import SwiftUI
2import PhotosUI

The PhotosUI framework provides tools to create customizable pickers for interacting with the photos library.

Building the Picker Interface

Struct ContentView with a Picker

You’ll typically define your user interface within a struct ContentView. Here’s how to set up the picker in the body property of a SwiftUI view, allowing users to select images.

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1struct ContentView: View {
2    // State variables to manage the selected image and picker presentation state
3    @State private var selectedImage: UIImage? = nil
4    @State private var isPickerPresented: Bool = false
5
6    var body: some View {
7        VStack {
8            if let selectedImage = selectedImage {
9                Image(uiImage: selectedImage)
10                    .resizable()
11                    .frame(width: 200, height: 200)
12            } else {
13                Text("No Image Selected")
14                    .font(.headline)
15            }
16
17            Button("Select Photo") {
18                isPickerPresented = true
19            }
20            .sheet(isPresented: $isPickerPresented) {
21                PhotoPicker(selectedImage: $selectedImage)
22            }
23        }
24    }
25}

In this example, the picker is wrapped in a sheet for smooth user interaction.

Creating the PhotoPicker Component

The PhotoPicker component, a custom implementation of UIViewControllerRepresentable, connects the photos picker to your app, enabling you to load and handle user-selected images.

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1struct PhotoPicker: UIViewControllerRepresentable {
2    @Binding var selectedImage: UIImage?
3
4    func makeUIViewController(context: Context) -> PHPickerViewController {
5        var config = PHPickerConfiguration(photoLibrary: .shared())
6        config.selectionLimit = 1
7        config.filter = .images
8
9        let picker = PHPickerViewController(configuration: config)
10        picker.delegate = context.coordinator
11        return picker
12    }
13
14    func updateUIViewController(_ uiViewController: PHPickerViewController, context: Context) {}
15
16    func makeCoordinator() -> Coordinator {
17        Coordinator(self)
18    }
19
20    // Coordinator to handle picker delegate methods
21    class Coordinator: NSObject, PHPickerViewControllerDelegate {
22        let parent: PhotoPicker
23
24        init(_ parent: PhotoPicker) {
25            self.parent = parent
26        }
27
28        func picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult]) {
29            picker.dismiss(animated: true)
30
31            guard let provider = results.first?.itemProvider, provider.canLoadObject(ofClass: UIImage.self) else { return }
32
33            provider.loadObject(ofClass: UIImage.self) { (image, error) in
34                DispatchQueue.main.async {
35                    if let uiImage = image as? UIImage {
36                        self.parent.selectedImage = uiImage
37                    }
38                }
39            }
40        }
41    }
42}

Here’s a breakdown of the matching parameters used in the picker configuration:

• selectionLimit determines if you want to select multiple photos or just one.
• filter = .images ensures that only images appear in the picker.

Handling Selected Images and Optimizing Memory Usage

Once the user selects an image, it’s important to manage memory usage effectively. Large images can consume significant resources, so resize or compress them before processing.

Example: Resizing Selected Images

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1extension UIImage {
2    // Resize images to optimize memory usage and improve app performance
3    func resize(to targetSize: CGSize) -> UIImage? {
4        UIGraphicsBeginImageContext(targetSize)
5        draw(in: CGRect(origin: .zero, size: targetSize))
6        let resizedImage = UIGraphicsGetImageFromCurrentImageContext()
7        UIGraphicsEndImageContext()
8        return resizedImage
9    }
10}

Resizing assets reduces the strain on your app’s storage and improves performance during display.

Supporting Multiple Images

If you want to select multiple photos, modify the picker configuration. Use an array to hold the selected images.

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1@State private var selectedImages: [UIImage] = []
2
3var body: some View {
4    PhotosPicker(selection: $selectedImages) {
5        Text("Select Multiple Photos")
6    }
7}

To display the selected images in a gallery, consider adding a ScrollView or LazyVGrid.

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1ScrollView {
2    LazyVGrid(columns: [GridItem(.adaptive(minimum: 100))]) {
3        ForEach(selectedImages, id: \ .self) { image in
4            Image(uiImage: image)
5                .resizable()
6                .frame(width: 100, height: 100)
7        }
8    }
9}

Tips for Efficient Implementation

• Asynchronous Data Handling: Always handle image data asynchronously to avoid blocking the main thread during loading.
• Frame Management: Use .frame modifiers to keep your UI consistent across screen sizes.
• Gallery Navigation: For advanced use cases, consider adding a control for navigating between selected images.
• Debugging Configuration: Use print statements to verify picker configuration and image selection during development.

Final Thoughts

The SwiftUI Image Picker is a powerful and flexible tool that enhances the user experience by integrating with the photo library. Whether you need to select multiple photos, optimize memory usage, or manage data efficiently, the photos selector makes it easy to handle user-selected content. By leveraging the features discussed in this guide, you can create robust, user-friendly apps with seamless image management.

Try implementing the SwiftUI Image Picker today and take your app’s functionality to the next level!