如何在Swift中使AdMob的singleton成为interstival?

我正在我的应用程序上使用AdMob interstival,并试图使实现更容易。

如果由于某些原因我不应该使用singleton来实现,请告诉我。

AdMob.h公司

#import <Foundation/Foundation.h>
#import "AdsID.h" 
@import GoogleMobileAds;

@interface AdMob : NSObject<GADBannerViewDelegate,GADInterstitialDelegate>

@property(nonatomic) GADBannerView *GADRecView; @property(nonatomic, strong) GADInterstitial *interstitial;

+ (AdMob *)sharedIncetance;
-(void)loadAdMobBanner:(UIViewController*)vc view:(UIView*)view x:(int)x y:(int)y;
-(void)loadAdMobInste:(UIViewController*)vc rate:(float)rate;

@end

#import "AdMob.h"

@implementation AdMob

static AdMob *sharedData_ = nil;

+ (AdMob *)sharedInstance{
    @synchronized(self){
        if (!sharedData_) {
            sharedData_ = [[AdMob alloc]init];
        }
    }
    return sharedData_;
}

- (id)init {
    self = [super init];
    if (self) {
        self.interstitial = [self createAndLoadInterstitial];
    }
    return self;
}

- (GADInterstitial *)createAndLoadInterstitial {

    GADInterstitial *interstitial =
    [[GADInterstitial alloc] initWithAdUnitID:@"XXXXXX"]; 
    interstitial.delegate = self;
    [interstitial loadRequest:[GADRequest request]];

    return interstitial;

}

-(void)loadAdMobInste:(UIViewController*)vc{

    if ([self.interstitial isReady]) {
        [self.interstitial presentFromRootViewController:vc];
    }

}

- (void)adViewDidReceiveAd:(GADBannerView *)bannerView {
    NSLog(@"Banner adapter class name: %@", bannerView.adNetworkClassName);
}

@end

视图控制器

[[AdMob sharedIncetance] loadAdMobInste:[self btk_parentViewController]];

更新
我可以用Swift实现它,但错误是“其视图不在窗口层次结构中!”因为我做了以下这些,广告没有出现:

2. 在ViewController中显示间隙
3. 在SecondViewController中加载间隙
4. 在SecondViewController中显示间隙(ad未显示,出现错误)

如果我使用Objective-C中的代码,则会显示ad,而不会出现错误。

AdMob公司

import Foundation
import GoogleMobileAds

class AdMob : NSObject, GADBannerViewDelegate, GADInterstitialDelegate{

    static var sharedData_: AdMob? = nil

    var interstitial: GADInterstitial?

    class func sharedInstance() -> AdMob? {
        let lockQueue = DispatchQueue(label: "self")
        lockQueue.sync {
            if sharedData_ == nil {
                sharedData_ = AdMob()
            }
        }
        return sharedData_
    }

    override init() {
        super.init()

        interstitial = createAndLoadInterstitial()

    }

    func createAndLoadInterstitial() -> GADInterstitial? {

        let interstitial = GADInterstitial(adUnitID: "ca-app-pub-3940256099942544/4411468910") 
        interstitial.delegate = self
        interstitial.load(GADRequest())

        return interstitial

    }

    func loadInste(_ vc: UIViewController?) {

        if interstitial?.isReady == true {
            self.interstitial?.present(fromRootViewController: vc!)
        }else{
            print("Ad was not realy")
        }
    }

    func interstitialDidDismissScreen(_ ad: GADInterstitial) {
        interstitial = createAndLoadInterstitial()
    }

    func interstitialDidReceiveAd(_ ad: GADInterstitial) {
        print("interstitialDidReceiveAd")
    }

    func interstitial(_ ad: GADInterstitial, didFailToReceiveAdWithError error: GADRequestError) {
        print("interstitial:didFailToReceiveAdWithError: \(error.localizedDescription)")
    }

    func interstitialWillPresentScreen(_ ad: GADInterstitial) {
        print("interstitialWillPresentScreen")
    }

    func interstitialWillDismissScreen(_ ad: GADInterstitial) {
        print("interstitialWillDismissScreen")
    }

    func interstitialWillLeaveApplication(_ ad: GADInterstitial) {
        print("interstitialWillLeaveApplication")
    }

}

class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    var navigationController: UINavigationController?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {

        window = UIWindow(frame: UIScreen.main.bounds)

        if let window = window {
            let mainVC = ViewController()
            navigationController = UINavigationController.init()
            navigationController = UINavigationController(rootViewController: mainVC)
            navigationController?.navigationBar.isHidden = true
            window.rootViewController = navigationController
            window.makeKeyAndVisible()
        }

        return true
    }
}

视图控制器

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        AdMob.sharedInstance()?.loadInste(self)
    }

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {

        let secondVC = SecondViewController()
        self.navigationController?.pushViewController(secondVC, animated: true)

        if AdMob.sharedInstance()?.interstitial?.isReady == true {
              AdMob.sharedInstance()?.interstitial?.present(fromRootViewController: self)
        } else {
            print("Ad wasn't ready")
        }
    }
}

import GoogleMobileAds

class SecondViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        self.view.backgroundColor = UIColor.white

        AdMob.sharedInstance()?.loadInste(self)

    }

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {

        self.navigationController?.popViewController(animated: true)

        if AdMob.sharedInstance()?.interstitial?.isReady == true {
            AdMob.sharedInstance()?.interstitial?.present(fromRootViewController: self)
        } else {
            print("Ad wasn't ready")
        }
    }
}