C# Winforms - Autocomplete (filter) combobox when typing

Question

I have a Combobox (cmbBairro) with the names of the neighborhoods of my city, which carries the values of a List (_Listneighborhoods). When the user tries to search a neighborhood by typing, he would like the values of Combobox to be filtered, regardless of the position of the typed characters!

When typing, for example: vis.

The Combobox would filter:

Good Vista

Garden Vista Alegre ...

How do I do that?

Answer 1

I didn’t understand very well if you wanted to filter in Combobox or Listbox, so I did both, this filter direct in Combobox:

public partial class Form1 : Form
{
    public string[] bairros = new string[] {
            "Acari",
            "Anchieta",
            "Barros Filho",
            "Bento Ribeiro",
            "Brás de Pina",
            "Bonsucesso",
            "Campinho",
            "Cavalcanti",
            "Cascadura",
            "Coelho Neto",
            "Colégio",
            "Complexo do Alemão",
            "Cordovil",
            "Costa Barros",
            "Engenheiro Leal",
            "Engenho da Rainha",
            "Guadalupe",
            "Higienópolis",
            "Honório Gurgel",
            "Irajá",
            "Jardim América",
            "Madureira",
            "Marechal Hermes",
            "Manguinhos",
            "Oswaldo Cruz"
        };
    public Form1()
    {
        InitializeComponent();
        _ListBairros.Items.AddRange(bairros);
        cmbBairro.TextChanged += CmbBairro_TextChanged;
    }
    private void CmbBairro_TextChanged(object sender, EventArgs e) {
        string texto = cmbBairro.Text;
        int a = cmbBairro.Items.Count;          
        if (a > 0) {
           int i = 0;
           while (i < a) {
                cmbBairro.Items.RemoveAt(0);                      
                i++;
          }
       }
        if (texto != "") {
            System.Text.RegularExpressions.Regex regex = new System.Text.RegularExpressions.Regex(texto, System.Text.RegularExpressions.RegexOptions.IgnoreCase);
            foreach (string lugar in bairros) {
                System.Text.RegularExpressions.Match resultado = regex.Match(lugar);
                if (resultado.Value != "") {
                    cmbBairro.Items.Add(lugar);
                }
            }
        }         
    }
}

This filter in Listbox:

public partial class Form1 : Form
{
    public string[] bairros = new string[] {
            "Acari",
            "Anchieta",
            "Barros Filho",
            "Bento Ribeiro",
            "Brás de Pina",
            "Bonsucesso",
            "Campinho",
            "Cavalcanti",
            "Cascadura",
            "Coelho Neto",
            "Colégio",
            "Complexo do Alemão",
            "Cordovil",
            "Costa Barros",
            "Engenheiro Leal",
            "Engenho da Rainha",
            "Guadalupe",
            "Higienópolis",
            "Honório Gurgel",
            "Irajá",
            "Jardim América",
            "Madureira",
            "Marechal Hermes",
            "Manguinhos",
            "Oswaldo Cruz"
        };
    public Form1()
    {
        InitializeComponent();
        _ListBairros.Items.AddRange(bairros);
        cmbBairro.TextChanged += CmbBairro_TextChanged;
    }

    private void CmbBairro_TextChanged(object sender, EventArgs e) {
        string texto = cmbBairro.Text;
        _ListBairros.Items.Clear();            
        if (texto != "") {
            System.Text.RegularExpressions.Regex regex = new System.Text.RegularExpressions.Regex(texto, System.Text.RegularExpressions.RegexOptions.IgnoreCase);
            foreach (string lugar in bairros) {
                System.Text.RegularExpressions.Match resultado = regex.Match(lugar);
                if (resultado.Value != "") {
                    _ListBairros.Items.Add(lugar);
                }
            }
        }         
    }
}

Inside the string[] neighborhoods is where the neighborhoods are.

This is my first participation in Stackoverflow, sorry for any error :P