How to return the Task<T> from HttpResponseMessage.Content.ReadAsStringAsync().ContinueWith() method?

Question

I am trying to Get/Post using the HttpClient Class and facing the following issues

1. Do not know how to return the Task from HttpResponseMessage.Content.ReadAsStringAsync().ContinueWith() method.

2. For some reason, it is keep on cancelling automatically

       private static Task<T> HttpClientSendAsync<T>(string url, object data, HttpMethod method, string contentType, CancellationToken token)
   {
       HttpRequestMessage httpRequestMessage = new HttpRequestMessage(method, url);
       RetryDelegatingHandler retryDelegatingHandler = new RetryDelegatingHandler();
       retryDelegatingHandler.PreAuthenticate = true;
       retryDelegatingHandler.Credentials = Credential;
       retryDelegatingHandler.Proxy = null;
   
       HttpClient httpClient = new HttpClient(retryDelegatingHandler);
       httpClient.Timeout = new TimeSpan(Constants.TimeOut);
   
       if (data != null)
       {
           byte[] byteArray = Encoding.ASCII.GetBytes(Helper.ToJSON(data));
           MemoryStream memoryStream = new MemoryStream(byteArray);
           httpRequestMessage.Content = new StringContent(new StreamReader(memoryStream).ReadToEnd(), Encoding.UTF8, contentType);
       }
   
       Task<HttpResponseMessage> httpResponseMessage = httpClient.SendAsync(httpRequestMessage);
       httpResponseMessage.ContinueWith((task) =>
           {
               if (!task.IsFaulted)
               {
                   HttpResponseMessage response = task.Result;
                   response.Content.ReadAsStringAsync().ContinueWith(
                   (stringTask) =>
                   {
                       if (!stringTask.IsFaulted)
                       {
                           return Helper.FromJSON<T>(stringTask.Result);
                       }
                       else
                       {
                           Logger.Log(string.Format("SendAsyncRequest Task IsFaulted: {0} \nException: {1}", typeof(T), task.Exception));
                           UpdateError(typeof(T).ToString());
   
                           return default(T);
                       }
                   });
               }
               else
               {
                   Logger.Log(string.Format("SendAsyncRequest Task IsFaulted: {0} \nException: {1}", typeof(T), task.Exception));
                   UpdateError(typeof(T).ToString());
   
                   return default(T);
               }
           });
   }
   

Update: It does work however still it does not work while trying to handle the Fault.

    return httpClient.SendAsync(httpRequestMessage).ContinueWith(task =>
    {
        var response = task.Result;
        return response.Content.ReadAsStringAsync().ContinueWith(stringTask =>
        {
            var json = stringTask.Result;
            return Helper.FromJSON<T>(json);
        });
    }).Unwrap();

Answer 1

Task.ContinueWith returns the continuation task: a Task or Task<T>. If I'm understanding the question, in your case here you could do something like this:

var continuation = httpResponseMessage.ContinueWith((task) =>
    {
        if (!task.IsFaulted)
        {
            HttpResponseMessage response = task.Result;
            return response.Content.ReadAsStringAsync().ContinueWith(
            (stringTask) =>
            {

            ...

and continuation will end up being a Task<Task<T>> which you can call .Unwrap() on to turn that into a proxy task Task<T>.