WinForms ComboBox DropDown and Autocomplete window both appear

Question

I\'ve got a ComboBox on a winforms app with this code:

comboBox1.AutoCompleteMode = AutoCompleteMode.SuggestAppend;
comboBox1.AutoCompleteSource         


        

Answer 1

WinForms ComboBox DropDown...the answer is this...
write below code in comboBox1 Enter event..

private void comboBox1_Enter(object sender, EventArgs e)
{
    comboBox1.DroppedDown = true;
}

Now for comboBox1 AutoComplete...
write this AutoComplete() in page load event..so it work...

public void AutoComplete()
{
    try
    {
        MySqlConnection conn = new 
        MySqlConnection("server=localhost;database=databasename;user
            id=root;password=;charset=utf8;");
        MySqlCommand cmd = new MySqlCommand("select distinct
            (columnName) from tablename", conn);
        DataSet ds = new DataSet();
        MySqlDataAdapter da = new MySqlDataAdapter(cmd);
        da.Fill(ds, "tablename");
        AutoCompleteStringCollection col = new
        AutoCompleteStringCollection();

        int i = 0;
        for (i = 0; i <= ds.Tables[0].Rows.Count - 1; i++)
        {
            col.Add(ds.Tables[0].Rows[i]["columnName"].ToString());
        }
        comboBox1.AutoCompleteSource = AutoCompleteSource.CustomSource;
        comboBox1.AutoCompleteCustomSource = col;
        comboBox1.AutoCompleteMode = AutoCompleteMode.Suggest;
        if (conn.State == ConnectionState.Open)
        {
            conn.Close();
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK,
    MessageBoxIcon.Error);
    }
}