pass jquery data to the controller and return values

Question

I need that when textbox loses focus, pass the value you have in it to my controller, in my controller I will return an object to jquery, so I can fill in the other fields.

I wonder how I could do that?

My controller method is this:

public UserValid RetornaUsuario(String matricula)
{
    UserValid valid = new UserValid();
    UserValidDAO dao = new UserValidDAO();
    valid = dao.Busca(matricula);

    return valid;
}

I was trying to do something this way:

function PassarMatricula() {
    var parametros = {
        _matricula : $('#txtMatricula').val(),      
    };

    $.ajax({
        url : 'Home/RetornaUsuario',
        datatype : 'json',
        contentType : "application/json; charset=utf-8",
        type : "POST",
        data : JSON.stringify(parametros),
        success : function(data) {  

        },
        error : function(error) {
        }
    });    
}

Answer 1

As stated in the comments by @Marconi, you can use Ajax to do this.

First you will send the data to your Action by Ajax, then do what you need and return the data via json for your view. An example would look like this:

Controller

        [HttpPost]
        public ActionResult BuscarCep(string cep)
        {
            var endereco = db.Endereco.FirstOrFefault(x => x.cep == cep);
            return Json(endereco, JsonRequestBehavior.AllowGet);
        }

View

<script>
        $('#txtCep').on('blur', function() {
            var cep= $('#txtCep').val();
            $.ajax({
                url: '@Url.Action("BuscarCep","Endereco")?cep=' + extensao,
                type: 'POST',
                success: function (data) {
                    //Preenche os inputs com os valores retornados aqui.
                    $('#txtEndereco').val(data.Endereco);
                }
            });
            return false;
        });
    </script>