ASP.NET Core API POST parameter is always null

Question

I have read the following:

• Asp.net Core Post parameter is always null
• asp.net webapi 2 post parameter is always null
• web-api POST body object

Answer 1

My particular issue was that the model binding was silently failing for a JSON model. (It was always null).

As I had the exact JSON being posted, I was able to debug it locally by running the web-service locally, and posting to my controller via cURL (can use POSTMAN).

Using the below code, I was able to see the exact exception occurring during serialization.

    [HttpPost]
    public IActionResult MyAction([FromBody] dynamic request)
    {            
        if (request != null)
        {
            try
            {
                var objAttempt =
                    JsonConvert.DeserializeObject(
                        JsonConvert.SerializeObject(request));
            }
            catch (Exception exception)
            {
                Console.WriteLine(exception);
                throw;
            }
        }