WebView: Schwerwiegender Fehler: unerwartet gefunden Null beim Entpacken ein optionaler Wert

Question

Ich versuche, meine WebView-URL zu ändern, aber jedes Mal bekomme ich fatal error: unexpectedly found nil while unwrapping an Optional value.

Was ist los? Vielen Dank.

@IBOutlet weak var myWebView: UIWebView! 
override func viewDidLoad() { 
    super.viewDidLoad() 
    myWebView.delegate = self 
    let url = NSURL (string: "http://cnn.com"); 
    let requestObj = NSURLRequest(url: url! as URL); 
    myWebView.loadRequest(requestObj as URLRequest); 

} 

func changeURL(urlIncome:String) { 
     let url = NSURL(string: urlIncome) 
     let requestObj = NSURLRequest(url: url as! URL) 
     myWebView.loadRequest(requestObj as URLRequest); 
} 

Mein AppDelegate Code:

class AppDelegate: UIResponder, UIApplicationDelegate { 

var window: UIWindow? 
var vc = ViewController() 


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

    UIApplication.shared.statusBarStyle = .lightContent 

    OneSignal.initWithLaunchOptions(launchOptions, appId: "", handleNotificationReceived: { (notification) in 

     let payload = notification?.payload 
     //let fullMessage = payload?.title 
     if let additionalData = payload?.additionalData, let actionURL = additionalData["url"] as? String { 
      self.vc.changeURL(urlIncome: actionURL); 
     } 

    }, handleNotificationAction: { (result) in 

     // This block gets called when the user reacts to a notification received 
     let payload = result?.notification.payload 
     let fullMessage = payload?.title 

     NSLog(fullMessage!); 

    }, settings: [kOSSettingsKeyAutoPrompt : true, kOSSettingsKeyInFocusDisplayOption : false]) 



    // Override point for customization after application launch. 
    return true 
} 

Answer 1

Der Grund, warum seine Krachen ist, weil Sie Kraft sind Casting-URL und URL-Anfrage.

Ändern Sie den Code unten

let url = NSURL (string: "http://cnn.com"); 
let requestObj = NSURLRequest(url: url! as URL); 
myWebView.loadRequest(requestObj as URLRequest); 

zu

let url = URL(string: "http://google.com")! 
myWebView.loadRequest(URLRequest(url: url)) 

Answer 2

Dies ist ein Code ich in Swift gerade getestet haben 3 mit Deployment Target 9.0 Set in Allgemeine Registerkarte in 8.2 XCode . Es funktioniert reibungslos, hoffe, das hilft:

Ihre ViewController.swift:

var myUrl = "" 

override func viewDidLoad() { 
     super.viewDidLoad() 

     if myUrl == "" { 
let url = URL (string: "http://cnn.com") 
webView.delegate = self 
webView.loadRequest(URLRequest(url: url!)) 
} else { 
let url = URL (string: myUrl) 
webView.delegate = self 
webView.loadRequest(URLRequest(url: url!)) 
} 

    } 

AppDelegate:

if let additionalData = payload?.additionalData, let actionURL = additionalData["url"] as? String { 
      let mainStoryboardIpad : UIStoryboard = UIStoryboard(name: "Main", bundle: nil) 
     let myVC : UIViewController = mainStoryboardIpad.instantiateViewControllerWithIdentifier("ViewController") as UIViewController 
myVC.myUrl = actionURL 
     self.window = UIWindow(frame: UIScreen.mainScreen().bounds) 
     self.window?.rootViewController = initialViewControlleripad 
     self.window?.makeKeyAndVisible() 
     } 

Denken Sie auch daran App Transport Security in Ihre Info.plist Datei hinzufügen um Arbitrary Loads zu erlauben (außer du hast das schon gemacht :)

<key>NSAppTransportSecurity</key> 
    <dict> 
     <key>NSAllowsArbitraryLoads</key> 
     <true/> 
    </dict>