How to display a SharePoint page in an iOS mobile app with Xamarin, WebView control and NTLM authentication

In this post, we will see an example of how to display a SharePoint page in the IOS mobile app using the WebView control using NTLM authentication. For this example, I have used my local SharePoint 2016 environment with a self-signed certificate and the Visual Studio for Mac.

Steps:

1. Add a WebView control to the ViewController.
   
2. Create a ConnectionDelegate to handle the SSL and Authentication. Please include the below section as a code sample:

   public class ConnectionDelegate : NSUrlConnectionDelegate
   {
       private readonly UIWebView _webView;
       private NSUrlRequest _request;
    
       public ConnectionDelegate(UIWebView parent, NSUrlRequest request)
       {
           _webView = parent;
           _request = request;
       }
    
       public override void WillSendRequestForAuthenticationChallenge(NSUrlConnection connection,
                    NSUrlAuthenticationChallenge challenge)
       {
                    
           if (challenge.ProtectionSpace.AuthenticationMethod == NSUrlProtectionSpace.AuthenticationMethodNTLM)
           {
    
            var credential = new NSUrlCredential("domain\\userid", "password", NSUrlCredentialPersistence.ForSession);
                        challenge.Sender.UseCredential(credential, challenge);
                        challenge.Sender.ContinueWithoutCredential(challenge);
    
                    }
           else if (challenge.ProtectionSpace.AuthenticationMethod == NSUrlProtectionSpace.AuthenticationMethodServerTrust)
           {
              challenge.Sender.UseCredential(NSUrlCredential.FromTrust(challenge.ProtectionSpace.ServerSecTrust), challenge);
                        challenge.Sender.ContinueWithoutCredential(challenge);
           }
    
           return;
        }
    
    }

3. Attach the custom delegate class to the WebView to handle the authentication.

   var urlComponents = new NSUrlComponents("https://portal.contoso.com");
   WebView.ShouldStartLoad = (webView, request, navType) =>
                {
    
                    var urlConnection = NSUrlConnection.FromRequest(request, new ConnectionDelegate(webView, request));
                    urlConnection.Start();
    
                    return true;
                };
                
   WebView.LoadRequest(new NSUrlRequest(urlComponents.Url));

4. Run the application to display the SharePoint page within the webview.