SwiftUIでインタースティシャル広告を実装する方法

インタースティシャル用のクラスを用意

import GoogleMobileAds    

#if DEBUG

let adUnitID = ""

#else

let adUnitID = ""

#endif

final class Interstitial: NSObject, GADFullScreenContentDelegate {

    private var interstitial: GADInterstitialAd?

    override init() {

        super.init()

        loadInterstitial()

    }

    func loadInterstitial(){

        let request = GADRequest()

        GADInterstitialAd.load(withAdUnitID:adUnitID,

                                    request: request,

                          completionHandler: { [self] ad, error in

                            if let error = error {

                              print("Failed to load interstitial ad: \(error.localizedDescription)")

                              return

                            }

                            interstitial = ad

                            interstitial?.fullScreenContentDelegate = self

                          }

        )

    }

    /// Tells the delegate that the ad failed to present full screen content.

    func ad(_ ad: GADFullScreenPresentingAd, didFailToPresentFullScreenContentWithError error: Error) {

        print("Ad did fail to present full screen content.")

    }

    /// Tells the delegate that the ad presented full screen content.

    func adDidPresentFullScreenContent(_ ad: GADFullScreenPresentingAd) {

        print("Ad did present full screen content.")

    }

    /// Tells the delegate that the ad dismissed full screen content.

    func adDidDismissFullScreenContent(_ ad: GADFullScreenPresentingAd) {

        print("Ad did dismiss full screen content.")

        loadInterstitial()

    }

    func showAd(){

        let root = UIApplication.shared.windows.first?.rootViewController

        interstitial?.present(fromRootViewController: root!)

    }

}

SWiftuiのボタン押下時に呼び出し

変数は用意してください

//保存ボタン

            Button(action:{

                self.showingAlert = true

            }){

                Image(systemName: "tray.and.arrow.down")

                Text("保存")

            }

            .padding(.trailing)

            .alert(isPresented: $showingAlert) {

                Alert(title: Text("保存しますか"),

                      primaryButton: .cancel(Text("キャンセル")),

                      secondaryButton: .default(Text("保存"),

                                                action: {

                                        interstitial.showAd()

                }))

            }