In what cases an object passed to action method equals null?

Question

i have an action method like so:
public IActionResult CreateShirt([FromBody] Person person)

{

// my code

}

some courses checks if the incoming object is null. but using postman i couldn't make person null no matter what i do with the request : no body , malformed json in the body , content-type header missing or wrong ... etc , in all those cases the either framework throw error but the action method is not executed , or the action is executed but the person is an object with default values. no null ever.

the question: can a passed object like this be null? in what cases? should i check the incoming object for null?

Answer 1

depends on the content-type. If json, then pass the value null as the body value. If a form post, then by definition the object is created and the post values applied to it.

Answer 2

Hi,

I recommend you check the Request content directly to confirm if the request is null or just there's issue with the model binding.

        public IActionResult CreateShirt([FromBody] Person person)
        {
            var requestStream = await Request.Content.ReadAsStreamAsync();
            string requestBody;
            using (var reader = new StreamReader(requestStream))
            {
                requestBody = await reader.ReadToEndAsync();
            }
        }