Kód: Vybrať všetko

private void textBox1_TextChanged(object sender, TextChangedEventArgs e)
        {
            if (textBox1.Text == String.Empty)
            {
                listBox1.SelectedItem = null;
                return;
            }

            for (int i = 0; i < listBox1.Items.Count; i++)
            {
                if (listBox1.Items[i].ToString().Contains(textBox1.Text))
                {
                    listBox1.SelectedItem = listBox1.Items[i];
                    break;
                }
                else
                    listBox1.SelectedItem = null;
            }
        }

Kód: Vybrať všetko

        If ListBox1.Items.Contains(TextBox1.Text) Then
            ListBox1.Visible = False
        End If

Kód: Vybrať všetko

Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
        Dim i As Integer
        If TextBox1.Text.Equals("") = False Then
            For i = 0 To ListBox1.Items.Count - 1
                If ListBox1.Items.Item(i).ToString.ToUpper.Contains(TextBox1.Text.ToUpper) Then
                    ListBox1.SelectedIndex = i
                    Exit Sub
                End If
            Next
        End If
        ListBox1.SelectedIndex = -1
End Sub