How to fill Textboxes?

Question

I wouldn’t want to use several if's to control a method of mine, unless there is no way to do it without the if's. I write in a list, the return of the BD that may or may not have banking information. The list returns me, Nome_Banco, Conta and Agencia. I need to fill out some textbox, but only if there is data. I’m having difficulties to do without using if's. See how it is currently.

if (vlstCorpFornecedor.Count > 0)
        {
            //string nm_banco = vlstCorpFornecedor[0].Banco.ToString();
            txtCpfCnpjCadFornecedor.Text = vlstCorpFornecedor[0].NuCPFCNPJ.ToString();
            txtNomeRazaoSocialCadFornecedor.Text = vlstCorpFornecedor[0].Nome.ToString();
            txtAgenciaCadFornecedor.Text = vlstCorpFornecedor[0].Agencia.ToString();
            txtContaCadFornecedor.Text = vlstCorpFornecedor[0].ContaCorrente.ToString();
            cmbBancos.SelectedValue = vlstCorpFornecedor[0].Banco.ToString();
            cmbBancos_SelectedIndexChanged(this, EventArgs.Empty);
        }   

Where vlstCorpFornecedor is my list. From here txtAgenciaCadFornecedor and I can only fill in if data exists or not. I can do it with if's and test if it is null or not, but the question is: Is there a way to do this without the if?

---

Responding to the Maniero.

These fields are displayed in a panel, like a "popup". These fields are in this panel. When in the form I type the CPF or CNPJ, then the panel is visible and these fields are filled after the search in the BD. The back list: CPF/CNPJ, Social Reason, Agency, Account, Bank Number and Bank Name(Institution).

Well, it turns out, since it’s an old rap sheet, I don’t always have the banking information. So when the panel is displayed (Visible), if any banking data comes null, will give error when assigning value to TextBoxes relative.

I’d like to avoid that mistake by already testing null in the information. if it comes null, the panel is displayed (Visible) with CPF/CNPJ and Social Reason filled and the other textboxes should come blank (empty) to be able to be filled manually(user type fields, agency, account, number and name of the bank (institution)).

Answer 1

If I understand correctly, you can avoid the if properly said but can not avoid a decision , so I will use a ternary operator (I’ll put only what matters, then you replicate to the other fields):

txtAgenciaCadFornecedor.Text = vlstCorpFornecedor[0].Agencia == null ? 
                                   "" : 
                                   vlstCorpFornecedor[0].Agencia.ToString();

So if the die is null he catches a string empty, otherwise take the die.

Are you sure you need the ToString()? If you don’t need it, you can simplify this by using the null-coalescing. Doesn’t seem to need.

txtAgenciaCadFornecedor.Text = vlstCorpFornecedor[0].Agencia ?? "";

An alternative would be to create an auxiliary method. Quick thinking could be a generic extension method that turns into string anything that received (gives p/ do even better than this), something like that:

public static string Coalesce<T>(this T obj, string defaultValue = "") {
    if (obj == null) return defaultValue;
    return obj.ToString();
}

I put in the Github for future reference.

Use:

txtAgenciaCadFornecedor.Text = vlstCorpFornecedor[0].Agencia.Coalesce();