Changing customer information via ID

Question

I cannot change customer information through ID

Code that makes the changes in the Database

         public void Atualizar(Contato contato)//metodo para atualizar dados: update   
    {
        OleDbParameter[] parametros = {
            new OleDbParameter("CODIGO", contato.Codigo),
            new OleDbParameter("NOME", contato.Nome),
            new OleDbParameter("FONE", contato.Fone),
            new OleDbParameter("EMAIL", contato.Email)
        };
        new ConexaoDAL().ConexaoAuto(parametros, "update Contato set NOME=@NOME,EMAIL=@EMAIL,FONE=@FONE  where CODIGO=@CODIGO ", "Erro ao atualizar ");
    }

Event Click page

      public void SalvaDados()
    {
        try
        {
            if (SalvarCodigo == null)
            {
                Crud d = new Crud();
                d.Gravar(new Contato(SalvarNome.Text, SalvarFone.Text, SalvarEmail.Text)); // gravando pessoa 
                Message.Text = "Cadastro salvo com sucesso";
            }
            else
            {
                int codigo = Convert.ToInt32(SalvarCodigo);

                Crud d = new Crud();
                d.Atualizar(new Contato(codigo, SalvarNome.Text, SalvarFone.Text, SalvarEmail.Text));
                Message.Text = "Cadastro alterado com sucesso";
            }
        }
        catch (Exception ex)
        {

            throw new Exception(Message.Text = ex.Message);
        }
    }

NOTE: when it gives the error it talks to convert, but I have tried to convert what is inside the textbox and even then it doesn’t work. aspx.

Answer 1

The whole code seems strange to me and there seems to be problems of design in it. It may be a matter of style and taste, but I would do all the method SalvarDados() in just 2 lines. I won’t try to teach this way because it can confuse those who don’t have a good general sense. I find it strange to create an instance of Crud only for this, but I know that there are those who like it. What is certainly a mistake is to have this try-catch. He is not solving any problem. In fact he is making it difficult to identify the error. Even if he had to capture an exception, shouldn’t be Exception.

You should not convert data you have no control over. You should use TryParse() or something similar, if it fails it has how to recover in the normal flow of the application. This can be seen in that question and in this too. Behold Differences between Parse vs Tryparse and What is the main difference between int. Parse() and Convert.Toint32()?. If it fails you must take some action but cannot save the data. The problem may be there.

But it’s no use trying to convert something that can’t be converted. What you might want to do is:

if (int.TryParse(SalvarCodigo.Text, var out codigo)) { //<=======note o .Text aqui
    var d = new Crud();
    d.Atualizar(new Contato(codigo, SalvarNome.Text, SalvarFone.Text, SalvarEmail.Text));
    Message.Text = "Cadastro alterado com sucesso";
} else {
    //aqui trata se o código é inválido
}

I put in the Github for future reference.

I have doubts and no other problems.