Swift UI – with UIKit

UIKit

UIKit is general iOS or tvOS UserInterface framework.

Before Swift UI, UIKit construct UserInterface in iOS app.

In this entry, I will explain combination with UIKit and Swift UI

Map

MKMapView is UIKit view.

UIViewRepresentable makeUIView, updateUIView

Actually, what we need to do is wrap UIKit in SwiftUI.

Create struct implement “UIViewRepresentable”

/// Creates a `UIView` instance to be presented.
func makeUIView(context: Self.Context) -> Self.UIViewType

/// Updates the presented `UIView` (and coordinator) to the latest
/// configuration.
func updateUIView(_ uiView: Self.UIViewType, context: Self.Context)

Example

This code is from “Creating and Combining Views“

MapView.swift

import SwiftUI
import MapKit

struct MapView: UIViewRepresentable {
    
    func makeUIView(context: Context) -> MKMapView {
        MKMapView(frame: .zero)
    }

    func updateUIView(_ uiView: MKMapView, context: Context) {
        let coordinate = CLLocationCoordinate2D(
            latitude: 34.011_286, longitude: -116.166_868)
        let span = MKCoordinateSpan(latitudeDelta: 2.0, longitudeDelta: 2.0)
        let region = MKCoordinateRegion(center: coordinate, span: span)
        uiView.setRegion(region, animated: true)
    }
}

struct MapView_Previews: PreviewProvider {
    static var previews: some View {
        MapView()
    }
}