POST passing Model MVC API

Question

I'm trying to send an object to an API and I got an error on it:

[HttpPost]
     public async Task<object> Upsert(int Base, int SubBase,object val)
            {
                using (var client = new HttpClient())
                {
             
                    client.BaseAddress = new Uri("http://localhost:50442/");
                    client.DefaultRequestHeaders.Clear();
                    HttpResponseMessage response = await client.PostAsJsonAsync("M01_Upsert/" + val, val);
                    response.EnsureSuccessStatusCode();
                    return response.Headers.Location;
    
                }
    
            }

and here is the API function I'm calling

 [HttpPost]
        public void M01_Upsert(object val)
        {
            var data = val;
        }

How do I call this properly? Am I doing it correctly? It gives me a error on method to call.

Answer 1

Try removing the [val] that you add to the post URL.

So change the following code line:

HttpResponseMessage response = await client.PostAsJsonAsync("M01_Upsert/" + val, val);

To:

HttpResponseMessage response = await client.PostAsJsonAsync("M01_Upsert", val);

On POST requests the payload should not be a part of the URL parameters. You pass it as a parameter to the PostAsJsonAsync method.