AdMob 横幅:严重错误:解开可选值包装时意外发现 nil

Question

我有一个加载网址的WKWebView，并且在WKWebView的底部显示了一个AdMob横幅视图。但是，当我运行应用程序时，我不断收到错误："致命错误：在解开可选值时意外发现 nil"。

这是我的代码：

@IBOutlet var bannerView: GADBannerView!
var webView : WKWebView!
var progressView : UIProgressView!
override func loadView() {
webView = WKWebView()
webView.navigationDelegate = self
view = webView
}
override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
if keyPath == "estimatedProgress" {
progressView.progress = Float(webView.estimatedProgress)
}
}
override func viewDidLoad() {
super.viewDidLoad()
let url = URL(string: "https://www.facebook.com")!
webView.load(URLRequest(url: url))
webView.allowsBackForwardNavigationGestures = true
navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Open", style: .plain, target: self, action: #selector(openTapped))
progressView = UIProgressView(progressViewStyle: .default)
progressView.sizeToFit()
let progressButton = UIBarButtonItem(customView: progressView)
let spacer = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)
let refresh = UIBarButtonItem(barButtonSystemItem: .refresh, target: webView, action: #selector(webView.reload))
toolbarItems = [progressButton, spacer, refresh]
navigationController?.isToolbarHidden = false
webView.addObserver(self, forKeyPath: #keyPath(WKWebView.estimatedProgress), options: .new, context: nil)
loadAd()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
func loadAd() {
bannerView.isHidden = true   //error happens at this line
bannerView.delegate = self
bannerView.adUnitID = "ca-app-pub-..." //id is here
bannerView.adSize = kGADAdSizeSmartBannerPortrait
bannerView.rootViewController = self
bannerView.load(GADRequest())
}
func openTapped() {
let ac = UIAlertController(title: "Open page…", message: nil, preferredStyle: .actionSheet)
ac.addAction(UIAlertAction(title: "apple.com", style: .default, handler: openPage))
ac.addAction(UIAlertAction(title: "hackingwithswift.com", style: .default, handler: openPage))
ac.addAction(UIAlertAction(title: "Cancel", style: .cancel))
present(ac, animated: true)
ac.popoverPresentationController?.barButtonItem = self.navigationItem.rightBarButtonItem
}
func openPage(action: UIAlertAction) {
let url = URL(string: "https://" + action.title!)!
webView.load(URLRequest(url: url))
}
func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
title = webView.title
}
func adViewDidReceiveAd(_ bannerView: GADBannerView) {
bannerView.isHidden = false
}
func adView(_ bannerView: GADBannerView, didFailToReceiveAdWithError error: GADRequestError) {
bannerView.isHidden = true
}

我无法弄清楚导致此错误的原因 - 控制台没有提供有关它所指的可选值的详细信息。在我尝试添加横幅广告之前，WKWebView 运行良好，因此我认为这与它有关。

更新：这显示在控制台中： 自横幅视图的打印说明： 表达式生成错误：错误：/var/folder/yn/kndnb8ws7bz1r0rc11fnpndw0000gn/T/./lldb/485/expr3.swift：1：99：错误：使用未声明的类型"GoogleMobileAds" Swift._DebuggerSupport.stringForPrintObject(Swift.UnsafePointer>(bitPattern： 0x11b5272a0(！.足尖( ^~~~~~~~~~~~~~~

Answer 1

我遇到了类似的问题，并且能够解决它。这可能会帮助某人...

我的问题是我没有设置IBOutlet变量，而是有

var bannerView: GADBannerView!

但相反，我需要使用 IBOutlet 将我的故事板中的视图附加到我的视图控制器

@IBOutlet var bannerView: GADBannerView!

我会确保它正确链接。

与此同时，我删除了以编程方式将横幅视图添加到故事板的代码。我认为如果您混合故事板并以编程方式添加它，这也会导致一些问题

Answer 2

很可能您没有连接"bannerView"IBOutlet变量和相关的故事板视图。