在我的iOS应用程序中，我想使用WKWebView在应用程序中包装外部URL 。此URL需要基本身份验证（它需要用户和密码凭据，如以下屏幕截图所示）。

经过一番调查，我尝试使用
didReceiveAuthenticationChallengemethod来启用自动
登录，因此我不了解它的工作原理。

这是我的代码。

import UIKit
import WebKit

class WebViewController: UIViewController, WKNavigationDelegate {

    var webView: WKWebView?

    private var request : NSURLRequest {
        let baseUrl = "https://unimol.esse3.cineca.it/auth/Logon.do"
        let URL = NSURL(string: baseUrl)!
        return NSURLRequest(URL: URL)
    }

    /* Start the network activity indicator when the web view is loading */
    func webView(webView: WKWebView,
                 didStartProvisionalNavigation navigation: WKNavigation){
        UIApplication.sharedApplication().networkActivityIndicatorVisible = true
    }

    /* Stop the network activity indicator when the loading finishes */
    func webView(webView: WKWebView,
                 didFinishNavigation navigation: WKNavigation){
        UIApplication.sharedApplication().networkActivityIndicatorVisible = false
    }

    func webView(webView: WKWebView,
                 decidePolicyForNavigationResponse navigationResponse: WKNavigationResponse,
                                                   decisionHandler: ((WKNavigationResponsePolicy) -> Void)){
        decisionHandler(.Allow)
    }

    func webView(webView: WKWebView, didReceiveAuthenticationChallenge challenge: NSURLAuthenticationChallenge, completionHandler: (NSURLSessionAuthChallengeDisposition, NSURLCredential?) -> Void) {

        if challenge.protectionSpace.host == "https://unimol.esse3.cineca.it/auth/Logon.do" {
            let user = "*******"
            let password = "******"
            let credential = NSURLCredential(user: user, password: password, persistence: NSURLCredentialPersistence.ForSession)
            challenge.sender?.useCredential(credential, forAuthenticationChallenge: challenge)
        }
    }

    override func viewDidLoad() {
        /* Create our preferences on how the web page should be loaded */
        let preferences = WKPreferences()
        preferences.javaScriptEnabled = false

        /* Create a configuration for our preferences */
        let configuration = WKWebViewConfiguration()
        configuration.preferences = preferences

        /* Now instantiate the web view */
        webView = WKWebView(frame: view.bounds, configuration: configuration)

        if let theWebView = webView {
            /* Load a web page into our web view */
            let urlRequest = self.request
            theWebView.loadRequest(urlRequest)
            theWebView.navigationDelegate = self
            view.addSubview(theWebView)
        }
    }
}

I’m facing with this exception:

Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Completion handler passed to -[MyUnimol.WebViewController webView:didReceiveAuthenticationChallenge:completionHandler:] was not called'

If I delete the didReceiveAuthenticationChallenge method, I’m able to reach
the URL but is gives me, obliviously, wrong credentials.

Anyone could explain me what I’m doing wrong please?