Configuring HttpClient

Content

[MAUI]
[IHttpClientFactory]

MAUI Android development machine setup

To provide access to your local computer services during development, you should configure your MAUI Android environment. On Android, a different type of message handler implementation is necessary, than on other platforms:

#if ANDROID

internal sealed class DevelopmentAndroidMessageHandler : Xamarin.Android.Net.AndroidMessageHandler
{
    protected override Javax.Net.Ssl.IHostnameVerifier GetSSLHostnameVerifier(Javax.Net.Ssl.HttpsURLConnection connection)
        => new CustomHostnameVerifier();

    private sealed class CustomHostnameVerifier : Java.Lang.Object, Javax.Net.Ssl.IHostnameVerifier
    {
        public bool Verify(string hostname, Javax.Net.Ssl.ISSLSession session)
        {
            return
                Javax.Net.Ssl.HttpsURLConnection.DefaultHostnameVerifier.Verify(hostname, session)
                || hostname == "10.0.2.2" && session.PeerPrincipal?.Name == "CN=localhost";
        }
    }
}

#endif

In your MAUI application, open your MauiProgram.cs file and add the follosing code:

#if DEBUG

        private static HttpMessageHandler GetLocalhostHandler()
        {
#if ANDROID
            DevelopmentAndroidMessageHandler handler = new DevelopmentAndroidMessageHandler();
#else
            HttpClientHandler handler = new HttpClientHandler();
#endif
            handler.ServerCertificateCustomValidationCallback = (message, cert, chain, errors) =>
            {
                if (cert != null && cert.Issuer.Equals("CN=localhost")) return true;
                return errors == System.Net.Security.SslPolicyErrors.None;
            };

            return handler;
        }

#endif

This code snippet handles your Windows, iOS, Android, TizenOS environment, when you need to instantiate a HttpClient for API calls. When configuring the OpenAI options, provide the factory method on the proper way:

builder.Services.AddForgeOpenAI(options => {
    options.AuthenticationInfo = builder.Configuration["OpenAI:ApiKey"]!;
#if DEBUG
    options.HttpMessageHandlerFactory = GetLocalhostHandler();
#endif
});

IHttpClientFactory

How to override the setup and settings of built-in IHttpClientFactory. This is useful, for example, if you implement resilement HTTP requests, retry policy or circuit-breaker with Polly