Passing json data to a WebApi with special characters results to null - json

Question

I have a json string that is being passed to a webapi, now the problem is, when I try adding special characters, the recieving object becomes null.
Here's I do it.
string json = JsonConvert.SerializeObject(ojectParams);
WebClient client = new WebClient();
client.Headers.Add("content-type", "application/json; charset=utf-8");
client.Headers.Add("AppKey", WebUser.AppKey);
client.Headers.Add("AppSecret", WebUser.AppSecret);
client.Headers.Add("AccountId", WebUser.AccountId.ToString());
if (!string.IsNullOrEmpty(WebUser.StoreId))
{
client.Headers.Add("StoreId", WebUser.StoreId);
}
var returnedStringObject = client.UploadString(string.Format("{0}/{1}", ConfigurationManager.AppSettings["Api"], endpoint), method, json);
Here's the json string:
"{\"Firstname\":\"kyv®\",\"Lastname\":\"sab®\"}"
I have added this one on the header hoping that it will fix the issue. But no luck with that.
charset=utf-8
On the recieving endpoint, the obj becomes null. But when I removed the special characters, the value is being passed.
[HttpPost]
public responseObj Endpoint(requestObj request)
Any ideas? Thanks!

Answer 1

You need to set the Encoding of the WebClient
client.Encoding = Encoding.UTF8;

Answer 2

Please see the code below.
Note: I did not use JsonConvert.SerializeObject and used HttpClient instead of WebClient
public static HttpRequestMessage CreateRequest(string requestUrl, HttpMethod method, String obj)
{
var request = new HttpRequestMessage
{
RequestUri = new Uri(requestUrl),
Method = method,
Content = new StringContent(obj, Encoding.UTF8, "application/json")
};
return request;
}
public static void DoAPI()
{
var client = new HttpClient();
var obj = "{\"Firstname\":\"kyv®\",\"Lastname\":\"sab®\"}";
var httpRequest = CreateRequest("mywebapiURL", HttpMethod.Post, obj);
var response = client.SendAsync(httpRequest).Result;
Console.WriteLine(response.Content.ReadAsStringAsync().Result);
}