Integer to String Conversion

Question

I’m creating a cafeteria system.
I created the login system and it’s working, when I went to create a page to create the logins, I’m having difficulties in converting the int for string - the txtNivel.Text does not come out of the red, follow the codes:

public int Codigo = 0;

private void Gravar(string Login, string Senha, int Nivel, string InfAdicionais)
{
    try
    {
        Dados objDados = new Dados();
        objDados.Gravar(Login, Senha, Nivel, InfAdicionais);

        txtLogin.Clear();
        txtSenha.Clear();
        txtNivel.Clear();
        txtInfAdicinais.Clear();

        string menssagem = "Seus dados foram gravados com sucesso.";

        MessageBox.Show(menssagem);
    }
    catch (Exception ex)
    {
        MessageBox.Show("Ocorreu um erro: " + ex.Message);
    }
}

private void btn_Adicionar_Click(object sender, EventArgs e)
{
    {
        if(!String.IsNullOrEmpty(txtLogin.Text) &&
           !String.IsNullOrEmpty(txtSenha.Text) &&
           !String.IsNullOrEmpty(txtNivel.Text))
            Gravar(txtLogin.Text, txtSenha.Text, txtNivel.Text**, txtInfAdicinais.Text);
        else
            MessageBox.Show("Ocorreu um erro");
    }
}

Dice:

//Usuarios

public class Usuarios

{
    public int IdUsuario { get; set; }
    public string Login { get; set; }
    public string Senha { get; set; }
    public int Nivel { get; set; }
    public string InfAdicionais { get; set; }
}

public void Gravar(string Login, string Senha, int Nivel, string InfAdicionais)
{
    using (SqlConnection objConexao = new SqlConnection(strConexao))
    {
        using (SqlCommand objCommand = new SqlCommand(strInsert, objConexao))
        {
            objCommand.Parameters.AddWithValue("@Login", Login);
            objCommand.Parameters.AddWithValue("@Senha", Senha);
            objCommand.Parameters.AddWithValue("@Nivel", Nivel);
            objCommand.Parameters.AddWithValue("@InfAdicionais", InfAdicionais);

            objConexao.Open();

            objCommand.ExecuteNonQuery();

            objConexao.Close();
        }
    }

}

Answer 1

You need to convert the value.

With the TryParse in addition to converting, it is possible to check if there has been success in converting as it returns a bool.

private void btn_Adicionar_Click(object sender, EventArgs e)
{

    {
        if
            (!String.IsNullOrEmpty(txtLogin.Text) &&
            !String.IsNullOrEmpty(txtSenha.Text) &&
            !String.IsNullOrEmpty(txtNivel.Text))

             if(!int.TryParse(txtNivel.Text, out int nivel))
             {
                  MessageBox.Show("o valor do nível não é númerico");
                  return;
             }

            Gravar(txtLogin.Text, txtSenha.Text, nivel, txtInfAdicinais.Text);

        else
        {
            MessageBox.Show("Ocorreu um erro");
        }
    }
}

EDIT

This feature is available from C#7, in previous versions it is necessary to declare the output variable outside the TryParse. Credits Marconcilio Souza

EDIT

If you want to know more about TryParse has this one great answer on the subject, it is worth reading.