How to change cell's ComboBox style in DataGridViewComboBoxColumn

Question

Cells in DataGridViewComboBoxColumn have ComboBoxStyle DropDownList. It means the user can only select values from the dropdown. The underlying control is ComboBox, so it can have style DropDown. How do I change the style of the underlying combo box in DataGridViewComboBoxColumn. Or, more general, can I have a column in DataGridView with dropdown where user can type?

Answer 1

void dataGridView1_EditingControlShowing(object sender, 
    DataGridViewEditingControlShowingEventArgs e)
{
    if (e.Control.GetType() == typeof(DataGridViewComboBoxEditingControl))
    {
        DataGridViewComboBoxEditingControl cbo = 
            e.Control as DataGridViewComboBoxEditingControl;
        cbo.DropDownStyle = ComboBoxStyle.DropDown;
    }
}

Problem with combobox and databound datagridview

Answer 2

Following solution works for me

private void dataGridView1_CellValidating(object sender, 
    DataGridViewCellValidatingEventArgs e) 
{
    if (e.ColumnIndex == Column1.Index) 
    {
        // Add the value to column's Items to pass validation
        if (!Column1.Items.Contains(e.FormattedValue.ToString())) 
        {
            Column1.Items.Add(e.FormattedValue);
            dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Value = 
                e.FormattedValue;
        }
    }
}

private void dataGridView1_EditingControlShowing(object sender, 
    DataGridViewEditingControlShowingEventArgs e) 
{
    if (dataGridView1.CurrentCell.ColumnIndex == Column1.Index) 
    {
        ComboBox cb = (ComboBox)e.Control;
        if (cb != null) 
        {
            cb.Items.Clear();
            // Customize content of the dropdown list
            cb.Items.AddRange(appropriateCollectionOfStrings);
            cb.DropDownStyle = ComboBoxStyle.DropDown;
        }
    }
}