Asp.net controller recieving null

My ASP.net controller is receiving null instead of passed in parameters 🙁
Js function:

function SendFormToController() {
            var username = document.getElementById("UsernameField").value;
            var email = document.getElementById("EmailField").value;
            var password = document.getElementById("PasswordField").value;

            var SendJson = {
                Username: username,
                Email: email,
                Password: password
            };
            console.log(JSON.stringify(SendJson));
            $.ajax({
                type: "POST",
                data: JSON.stringify(SendJson),
                url: "Register/Register",
                contentType: "application/json"
            });
        }

Data is present when I console log it. But in the controller, I get – https://prnt.sc/u2mpa6
And it is for every field here

Answers:

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Method 1

First; Did you add the [HttpPost] attribute on top of your controller method?

Second; If you submit it in ‘querystring’ format: Username=xx&Password=yy&… and use (HttpGet). Does that work?

If you need to do a POST (and not want to use GET) you can create an object with all your current arguments and use the [FromBody] attribute:

[Route("Register")]
[HttpPost]
public ResultData Register([FromBody] RegisterRequest data) {
   //Your logic...
}

And client (JavaScript) side:

let url = 'http://...';
$.post(url, { Username: name, Password: pass, What: ever  }, function (result) {
    //Do some nice stuff
})
.fail(function (error) {
    //Oh no! Show error.statusText
});

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0