Asp.net Client - Server POST and Response (405 Method Not Allowed)

Question

Why doesn't my server return the same value to the client as he sends?

On the server my ApiController looks like that:

public void Post(byte[] value)
    {
        Request.CreateResponse<byte[]>(HttpStatusCode.OK, value);
    }

- Shouldn't it return the data from POST to the client?
And on the client side I've got:

using (var client = new WebClient())
{
    byte[] value = { 16, 32 };

    client.UploadDataCompleted += delegate
    {
        Debug.WriteLine(Encoding.Default.GetString(response));
    };

    response = client.UploadData("http://localhost:52117/", value);
}

The error message:

The remote server returned an error: (405) Method Not Allowed.

I just started with ASP.net. I am trying to make it work for hours now lol.
I've tried to follow tutorial with products and stuff, but it's not even similar.

Edit: I even tried this thing Here where it says:

The return value from the action is converted to an HttpResponseMessage.

If return type is HttpResponseMessage, pass through (as response to client) .

public HttpResponseMessage Post(byte[] value)
{
    var msg = new HttpResponseMessage();
    msg.Content = new ByteArrayContent(value);
    return msg;
}

Nothing works..

Answer 1

you might missing something

Refer to this link for more idea, https://trentgardner.net/net/asp-net-webmethods-with-jquery-and-ajax/

try

 [System.Web.Services.WebMethod]
public void Post(byte[] value)
    {
        Request.CreateResponse<byte[]>(HttpStatusCode.OK, value);
    }