PATCH Richieste asincrone con la classe Windows.Web.Http.HttpClient

Ho trovato come fare un PATCH "personalizzato". richiesta con il precedente System.Net.Http.HttpClient lezione qui, e poi giocherellare fino a farlo funzionare nel Windows.Web.Http.HttpClient classe, in questo modo:

public async Task<HttpResponseMessage> PatchAsync(HttpClient client, Uri requestUri, IHttpContent iContent) {
    var method = new HttpMethod("PATCH");

    var request = new HttpRequestMessage(method, requestUri) {
        Content = iContent
    };

    HttpResponseMessage response = new HttpResponseMessage();
    // In case you want to set a timeout
    //CancellationToken cancellationToken = new CancellationTokenSource(60).Token;

    try {
         response = await client.SendRequestAsync(request);
         // If you want to use the timeout you set
         //response = await client.SendRequestAsync(request).AsTask(cancellationToken);
    } catch(TaskCanceledException e) {
        Debug.WriteLine("ERROR: " + e.ToString());
    }

    return response;
}

Aggiornamento: Vedi la risposta di SSX-SL33PY di seguito per una soluzione ancora migliore, che fa la stessa cosa.

Puoi scrivere lo stesso metodo del metodo di estensione, quindi puoi invocarlo direttamente sull'oggetto HttpClient:

public static class HttpClientExtensions
{
   public static async Task<HttpResponseMessage> PatchAsync(this HttpClient client, Uri requestUri, HttpContent iContent)
   {
       var method = new HttpMethod("PATCH");
       var request = new HttpRequestMessage(method, requestUri)
       {
           Content = iContent
       };

       HttpResponseMessage response = new HttpResponseMessage();
       try
       {
           response = await client.SendAsync(request);
       }
       catch (TaskCanceledException e)
       {
           Debug.WriteLine("ERROR: " + e.ToString());
       }

       return response;
   }
}

Utilizzo:

var responseMessage = await httpClient.PatchAsync(new Uri("testUri"), httpContent);

Vorrei estendere la risposta di @alexander-pacha e suggerire di aggiungere la seguente classe di estensione da qualche parte in una libreria comune. Che questa sia una libreria comune per un progetto/client/framework/... è qualcosa che dovrai capire da solo.

    public static class HttpClientExtensions
    {
        /// <summary>
        /// Send a PATCH request to the specified Uri as an asynchronous operation.
        /// </summary>
        /// 
        /// <returns>
        /// Returns <see cref="T:System.Threading.Tasks.Task`1"/>.The task object representing the asynchronous operation.
        /// </returns>
        /// <param name="client">The instantiated Http Client <see cref="HttpClient"/></param>
        /// <param name="requestUri">The Uri the request is sent to.</param>
        /// <param name="content">The HTTP request content sent to the server.</param>
        /// <exception cref="T:System.ArgumentNullException">The <paramref name="client"/> was null.</exception>
        /// <exception cref="T:System.ArgumentNullException">The <paramref name="requestUri"/> was null.</exception>
        public static Task<HttpResponseMessage> PatchAsync(this HttpClient client, string requestUri, HttpContent content)
        {
            return client.PatchAsync(CreateUri(requestUri), content);
        }

        /// <summary>
        /// Send a PATCH request to the specified Uri as an asynchronous operation.
        /// </summary>
        /// 
        /// <returns>
        /// Returns <see cref="T:System.Threading.Tasks.Task`1"/>.The task object representing the asynchronous operation.
        /// </returns>
        /// <param name="client">The instantiated Http Client <see cref="HttpClient"/></param>
        /// <param name="requestUri">The Uri the request is sent to.</param>
        /// <param name="content">The HTTP request content sent to the server.</param>
        /// <exception cref="T:System.ArgumentNullException">The <paramref name="client"/> was null.</exception>
        /// <exception cref="T:System.ArgumentNullException">The <paramref name="requestUri"/> was null.</exception>
        public static Task<HttpResponseMessage> PatchAsync(this HttpClient client, Uri requestUri, HttpContent content)
        {
            return client.PatchAsync(requestUri, content, CancellationToken.None);
        }
        /// <summary>
        /// Send a PATCH request with a cancellation token as an asynchronous operation.
        /// </summary>
        /// 
        /// <returns>
        /// Returns <see cref="T:System.Threading.Tasks.Task`1"/>.The task object representing the asynchronous operation.
        /// </returns>
        /// <param name="client">The instantiated Http Client <see cref="HttpClient"/></param>
        /// <param name="requestUri">The Uri the request is sent to.</param>
        /// <param name="content">The HTTP request content sent to the server.</param>
        /// <param name="cancellationToken">A cancellation token that can be used by other objects or threads to receive notice of cancellation.</param>
        /// <exception cref="T:System.ArgumentNullException">The <paramref name="client"/> was null.</exception>
        /// <exception cref="T:System.ArgumentNullException">The <paramref name="requestUri"/> was null.</exception>
        public static Task<HttpResponseMessage> PatchAsync(this HttpClient client, string requestUri, HttpContent content, CancellationToken cancellationToken)
        {
            return client.PatchAsync(CreateUri(requestUri), content, cancellationToken);
        }

        /// <summary>
        /// Send a PATCH request with a cancellation token as an asynchronous operation.
        /// </summary>
        /// 
        /// <returns>
        /// Returns <see cref="T:System.Threading.Tasks.Task`1"/>.The task object representing the asynchronous operation.
        /// </returns>
        /// <param name="client">The instantiated Http Client <see cref="HttpClient"/></param>
        /// <param name="requestUri">The Uri the request is sent to.</param>
        /// <param name="content">The HTTP request content sent to the server.</param>
        /// <param name="cancellationToken">A cancellation token that can be used by other objects or threads to receive notice of cancellation.</param>
        /// <exception cref="T:System.ArgumentNullException">The <paramref name="client"/> was null.</exception>
        /// <exception cref="T:System.ArgumentNullException">The <paramref name="requestUri"/> was null.</exception>
        public static Task<HttpResponseMessage> PatchAsync(this HttpClient client, Uri requestUri, HttpContent content, CancellationToken cancellationToken)
        {
            return client.SendAsync(new HttpRequestMessage(new HttpMethod("PATCH"), requestUri)
            {
                Content = content
            }, cancellationToken);
        }

        private static Uri CreateUri(string uri)
        {
            return string.IsNullOrEmpty(uri) ? null : new Uri(uri, UriKind.RelativeOrAbsolute);
        }
    }

In questo modo non stai aspettando e sospendendo l'esecuzione in una classe di estensione statica, ma la gestisci come se stessi davvero facendo un PostAsync o un PutAsync chiamata. Hai anche gli stessi sovraccarichi a tua disposizione e stai lasciando il HttpClient gestire tutto ciò per cui è stato progettato.