Invoking the ASP.NET Web API from a client in .NET 3.5

It's actually pretty simple. I followed this post, but basically you just have to do the following.

http://www.thepicketts.org/2012/11/how-to-access-webapi-from-a-net-3-5-client-in-c/

public static object postWebApi(object data, Uri webApiUrl) {
    // Create a WebClient to POST the request
    WebClient client = new WebClient();

    // Set the header so it knows we are sending JSON
    client.Headers[HttpRequestHeader.ContentType] = "application/json";

    // Serialise the data we are sending in to JSON
    string serialisedData = JsonConvert.SerializeObject(data);

    // Make the request
    var response = client.UploadString(webApiUrl, serialisedData);

    // Deserialise the response into a GUID
    return JsonConvert.DeserializeObject(response);
}