Help - C# how to update combobox? type autocomplete

Question

First I am developing a C# system and using Sql Server as a database.

I would like to accomplish the following task: When something is typed in the combobox I update the itself, by means of a search in the bank, example:

I type A in the combobox and load it with the return of the selecte.

Other Example: Similar to google search, American, extra and etc. Style an autocomplete, and it is necessary to use the combobox, because in it I have to bring the name in the display and the code in the value of the combobox.

Like a autocomplete, but I need it to be a combobox because in it I bring together a code.

I programmed it this way:

exe:

comboBox.DataSource = dataTable;
comboBox.DisplayMember = "Nome";
comboBox.ValueMember = "codigo;

Inside the combobox Textchanged.

select is right and the datatable is right, but I’m having the following problem the combobox takes the first line that returns and doesn’t let me keep typing, nor does it change to bottom record (OBS: Returns more than one line) nor at least it shows the list, simply "lock" in the first line.

I do not know if you have to configure some property of the combobox or perform in a specific event ...

First I had made an autocomplete in a textbox, it works but I can’t get the option code is selected.

And I didn’t want to load the combobox with all the records. So it’s not something heavy.

More specifically I’m making a form related to sale, and I’m researching the customer this way. I don’t even know if it has like.

I am grateful for any suggestion.

Updating --

combobox textChanged codex

    private void cmbNome_Cliente_TextChanged(object sender, EventArgs e)
    {
        Cliente cliente = new Cliente();
        cliente.Nome = cmbNome_Cliente.Text;
        cliente.Razao_social = cmbNome_Cliente.Text;


        cmbNome_Cliente.DataSource = cliente.CarregaClienteNome(); "Isso retorna um dataTable"
        cmbNome_Cliente.DisplayMember = "Nome - Razao Social";
        cmbNome_Cliente.ValueMember = "Código";
    }

//Search Customer for Combobox by name ##updated

    public DataTable CarregaClienteNome()
    {
        SqlDataAdapter da = new SqlDataAdapter();
        DataTable dt = new DataTable();

        try
        {
            conn.Open();
            cmd.Connection = conn;

            cmd.CommandText = "select top(5) cli.cod_cliente as Código, ";
            cmd.CommandText += "(case when pes.cod_tipo_pessoa = 1 then Nome else Razao_Social end) as 'Nome - Razao Social' ";
            cmd.CommandText += "from tab_Pessoa pes ";
            cmd.CommandText += "inner join tab_Cliente cli on pes.cod_pessoa = cli.cod_pessoa ";
            cmd.CommandText += "where pes.nome like '" + Nome + "%' or pes.razao_social like '" + Razao_social + "%'";
            cmd.CommandText += " order by 'Nome - Razao Social'";

            da.SelectCommand = cmd;
            da.Fill(dt);
            cmd.ExecuteNonQuery();
        }
        catch (Exception e)
        {
            MessageBox.Show(e.Message);
        }
        finally
        {
            conn.Close();
        }

        return dt;
    }

//Autocomplete - test I’ve done with autocomplete in a textbox, it’s working. However I can’t get the code

private void txtTeste_TextChanged(object sender, EventArgs e)
    {
        Cliente cliente = new Cliente();

        cliente.Nome = txtTeste.Text;
        cliente.Razao_social = txtTeste.Text;

        DataTable dt = new DataTable();

        var source = new AutoCompleteStringCollection();

        dt =cliente.CarregaClienteNome();

        for (int i = 0; i < dt.Rows.Count; i++)
        {
            source.Add(dt.Rows[i][1].ToString());
        }


        txtTeste.AutoCompleteCustomSource = source;            

    }

Answer 1

At friend’s request @Luisfelipemicaidejesus I will put an example using autoComplete.

 <asp:TextBox ID="txtPesquisarHipotese" runat="server" Width="300px"></asp:TextBox>
 <asp:HiddenField ID="hdfPesquisarHipotese" runat="server" Value="" />

txtPesquisarHipothesis ==> Textbox that will put Autocomplete.

hdfPesquisarHipothesis ==> hiden that will hide the User Selection.

When I use the function select i take the value that the user selected and save in Hiddenfield.

If you need more details, specify in the comments that I edit the answer.

$(function () {
    $("#<%=txtPesquisarHipotese.ClientID%>").autocomplete(
                    {
                        source: function (request, response) {
                            $.ajax({
                                url: '<%=ResolveUrl("../ws/AutoComplete.asmx/GetEscopo")%>',
                                data: JSON.stringify({
                                    'prefixText': request.term
                                }),
                                dataType: "json",
                                type: "POST",
                                contentType: "application/json; charset=utf-8",
                                success: function (data) {
                                    response($.map(data.d, function (item) {
                                        return {
                                            label: item.split('#')[1],
                                            val: item.split('#')[0]
                                        }
                                    }))
                                },
                                error: function (response) {
                                    alert(response.responseText);
                                },
                                failure: function (response) {
                                    alert(response.responseText);
                                }
                            });
                        },
                        select: function (e, i) {
                            $("#<%=hdfPesquisarHipotese.ClientID%>").val(i.item.val);
                        },
                        minLength: 1
                    });
});

Code inside my file . asmx Note: If you want you can use the url to access a Webmethod inside your page.

    [WebMethod]
    public string[] GetEscopo(string prefixText)
    {
        SqlConnection conn = null;
        List<string> resultado = new List<string>();

        try
        {
            using (conn = new SqlConnection(Conexao))
            {
                SqlCommand cmd = new SqlCommand("select Escopo from Escopos where Escopos.Escopo like @prefixText group by Escopo order by Escopo", conn);
                SqlParameter param = new SqlParameter();
                cmd.Parameters.Add("@prefixText", SqlDbType.VarChar);
                cmd.Parameters["@prefixText"].Value = "%" + prefixText + "%";
                conn.Open();

                using (SqlDataReader dr = cmd.ExecuteReader())
                {
                    while (dr.Read())
                    {
                        resultado.Add(dr["Escopo"].ToString());
                    }
                    dr.Close();
                }
            }
        }
        catch { }
        finally
        {
            if (conn != null)
            {
                conn.Close();
            }
        }
        return resultado.ToArray();
    }