Leave Selected specific item Combobox C# Winforms Visual Studio 2017

Question

I am developing an application that contains a customer register. In this register there is a ComboBox listing the cities in the database.

My question is this: How do I leave 'setate' the name of a city specifies?

For example: first city that lists by default is 'ABADIA DE GOIAS', but I would like the city that appears selected to be 'SAO PAULO', that is there through my list. How can I do that?

Code listing cities in Combobox:

String nomeConexao = LoginInfo.StringConexao;
String string_conn = ConfigurationManager.ConnectionStrings[nomeConexao].ConnectionString;
SqlConnection conn = new SqlConnection(string_conn);

String scom = "SELECT COD, CIDADE FROM CODMUNICIPIO ORDER BY CIDADE";

SqlDataAdapter da = new SqlDataAdapter(scom, conn);

DataTable dtResultado = new DataTable();
dtResultado.Clear();
CbCidade.DataSource = null;
da.Fill(dtResultado);

CbCidade.DataSource = dtResultado;
CbCidade.ValueMember = "COD";
CbCidade.DisplayMember = "CIDADE";
CbCidade.SelectedItem = "";
CbCidade.Refresh();

Answer 1

You can set the property SelectedValue:

CbCidade.SelectedValue = 1; //supondo que 1 seja código de Sao Paulo

or you can set Text as well:

CbCidade.Text = "SAO PAULO";

Although I find it unnecessary to run a new query to search for the city code that should be parameterized, you should do so:

String sql2 = "SELECT COD FROM  CODMUNICIPIO WHERE CIDADE = '" + CidadeEmpresa + "'"; 

SqlCommand cmd2 = new SqlCommand(sql2, conn); 
SqlDataReader leitor = cmd2.ExecuteReader();
 if (leitor.HasRows)
 {
      leitor.Read();
      this.CbCidade.SelectedValue = leitor["COD"].ToString();
 }

The Correct, would you store the Company City Code in the variable CidadeEmpresa and not her name, so would just:

this.CbCidade.SelectedValue = CidadeEmpresa;

and if it is still not changing what is stored in the variable, just do so:

this.CbCidade.Text = CidadeEmpresa;