How to send a Post body in the HttpClient request in Windows Phone 8?

Question

I have written the code below to send headers, post parameters. The problem is that I am using SendAsync since my request can be GET or POST. How can I add POST Body to this peice of code so that if there is any post body data it gets added in the request that I make and if its simple GET or POST without body it send the request that way. Please update the code below:

HttpClient client = new HttpClient();  // Add a new Request Message HttpRequestMessage requestMessage = new HttpRequestMessage(RequestHTTPMethod, ToString());  // Add our custom headers if (RequestHeader != null) {     foreach (var item in RequestHeader)     {          requestMessage.Headers.Add(item.Key, item.Value);      } }  // Add request body   // Send the request to the server HttpResponseMessage response = await client.SendAsync(requestMessage);  // Get the response responseString = await response.Content.ReadAsStringAsync(); 

Answer 1

UPDATE 2:

From @Craig Brown:

As of .NET 5 you can do:
requestMessage.Content = JsonContent.Create(new { Name = "John Doe", Age = 33 });

See JsonContent class documentation

UPDATE 1:

Oh, it can be even nicer (from this answer):

requestMessage.Content = new StringContent("{\"name\":\"John Doe\",\"age\":33}", Encoding.UTF8, "application/json"); 

This depends on what content do you have. You need to initialize your requestMessage.Content property with new HttpContent. For example:

... // Add request body if (isPostRequest) {     requestMessage.Content = new ByteArrayContent(content); } ... 

where content is your encoded content. You also should include correct Content-type header.

Answer 2

I implemented it in the following way. I wanted a generic MakeRequest method that could call my API and receive content for the body of the request - and also deserialise the response into the desired type. I create a Dictionary<string, string> object to house the content to be submitted, and then set the HttpRequestMessage Content property with it:

Generic method to call the API:

    private static T MakeRequest<T>(string httpMethod, string route, Dictionary<string, string> postParams = null)     {         using (var client = new HttpClient())         {             HttpRequestMessage requestMessage = new HttpRequestMessage(new HttpMethod(httpMethod), $"{_apiBaseUri}/{route}");              if (postParams != null)                 requestMessage.Content = new FormUrlEncodedContent(postParams);   // This is where your content gets added to the request body               HttpResponseMessage response = client.SendAsync(requestMessage).Result;              string apiResponse = response.Content.ReadAsStringAsync().Result;             try             {                 // Attempt to deserialise the reponse to the desired type, otherwise throw an expetion with the response from the api.                 if (apiResponse != "")                     return JsonConvert.DeserializeObject<T>(apiResponse);                 else                     throw new Exception();             }             catch (Exception ex)             {                 throw new Exception($"An error ocurred while calling the API. It responded with the following message: {response.StatusCode} {response.ReasonPhrase}");             }         }     } 

Call the method:

    public static CardInformation ValidateCard(string cardNumber, string country = "CAN")     {          // Here you create your parameters to be added to the request content         var postParams = new Dictionary<string, string> { { "cardNumber", cardNumber }, { "country", country } };         // make a POST request to the "cards" endpoint and pass in the parameters         return MakeRequest<CardInformation>("POST", "cards", postParams);     }