Calling c# method in javascript

Question

I created a method that calls data from a database in C#. How can I call this method in Javascript ?

Follows code

[WebMethod]
    public copa recuperaDados(int cAno)
    {
        var con = ConfigurationManager.ConnectionStrings["Data Source=(localdb)/MSSQLLocalDB;Initial Catalog=C:/USERS/BERNARDO/DOCUMENTS/COPA.MDF;Integrated Security=True;Connect Timeout=30;Encrypt=False;TrustServerCertificate=True;ApplicationIntent=ReadWrite;MultiSubnetFailover=False"].ToString();

        copa selecionada = new copa();

        using(SqlConnection myCon = new SqlConnection(con))
        {
            string q = "Select * from copa where ano = @ano";
            SqlCommand cmd = new SqlCommand(q, myCon);
            cmd.Parameters.AddWithValue("@ano", cAno);

            using(SqlDataReader reader = cmd.ExecuteReader())
            {
                while (reader.Read())
                {
                    selecionada.sede = reader["sede"].ToString();
                    selecionada.campeao = reader["campeao"].ToString();
                    selecionada.vice = reader["vice"].ToString();
                }

                myCon.Close();
            }
            return selecionada;
        }
    }

javascript

<script type="text/javascript">
$("#CopaList").change(function () {
    $("#msg").text("A copa de " + $("#CopaList option:selected").text() + " teve como país(es) sede(s) : " + 

        + "O Campeão foi " +  + "O Vice Campeão foi " + 
       )
})

Answer 1

Friend you can use ajax to get the data from the backend without having to refresh the page:

$("#CopaList").change(function () {
  $.ajax({
    type: "GET",
    url: "SuaPagina.aspx/PreencheCampo",
    data: JSON.stringify({ cAno: $("#CopaList option:selected").text() }),
    contentType: "application/json; charset=utf-8",
    success: (response) => {
      $("#msg").text("A copa de " + $("#CopaList option:selected").text() + " teve como país(es) sede(s) : " + response.selecionada.sede + ".O Campeão foi " + response.selecionada.campeao + ".O Vice Campeão foi " + response.selecionada.vice);
    },
    error: (response) => {
      console.log(response);
    }
  })
})

I hope it helps.

Answer 2

recovered Data is the name of the backend function. So change the code of @Maycon F. Castro to "Suapagina.aspx/recoveredDados".

But, you need to see the rest of the code. You need to debug it to see if it is entering the recovered functionDados.

In the browser, in the console (no elements) does not generate any errors? If you call directly in the browser by the url "Suapagina.aspx/recuperaDados? cano=2020"