Null response Xamarin android application using web api - asp.net-web-api

Question

Hi I am just learning Xamarin android development and I just want to CRUD operation but I am stuck that I am unable to get any response from webapi. I have tested my api using SOAPUI and response is ok from that.
[HttpPost]
public HttpResponseMessage CreateEmpAttandance(string value)
{
if (value != "1234")
{
string json = #"{ data: 'Emp Code is not valid.'}";
var jObject = JObject.Parse(json);
var response = Request.CreateResponse(HttpStatusCode.OK);
response.Content = new StringContent(jObject.ToString(), System.Text.Encoding.UTF8, "application/json");
return response;
}
else
{
string json = #"{ data: 'data save sucessfully.'}";
var jObject = JObject.Parse(json);
var response = Request.CreateResponse(HttpStatusCode.OK);
response.Content = new StringContent(jObject.ToString(), System.Text.Encoding.UTF8, "application/json");
return response;
}
}
this is api code and below is my android application code but I am getting null response exception.
public async Task SaveTodoItemAsync(string EmpCode)
{
try
{
string url = "http://192.168.1.9/attandanceapi/api/attandance?value=12132";
var uri = new Uri(string.Format(url));
var json = JsonConvert.SerializeObject(EmpCode);
var content = new StringContent(EmpCode, Encoding.UTF8, "application/json");
HttpResponseMessage response = null;
response = await client.PostAsync(url, content);
var responses = response;
}
catch (Exception ex)
{
var w = ex.ToString();
}
}

Answer 1

I think we have problem here. You are trying to create content from string not from Json.
var content = new StringContent(EmpCode, Encoding.UTF8, "application/json");
try this:
var content = new StringContent(json, Encoding.UTF8, "application/json");
Edit:
I cannot see your default headers so if you don't have them - just add.
client.DefaultRequestHeaders.Add("Accept", "application/json");