Windows Forms DataGridView control have different control types in the same column

Question

Is it possible to do the following in a DataGridView:

In the same column I want to change the control type of each row between DataGridViewTextBoxColumn and DataGridViewComboBoxColumn?

(this is because sometimes I want to display a drop down list and other times I just want the user to enter a freehand value).

Thanks,

P.S. I am using C#

Answer 1

I've recently had a similar usecase, and ended up writing something like the below code:

Write a custom Cell and Column class, and override the EditType and InitializeEditingControl methods on the cell, to return different controls as appropriate (here I'm just databinding to a list of a custom class with .useCombo field indicating what control to use):

// Define a column that will create an appropriate type of edit control as needed.
public class OptionalDropdownColumn : DataGridViewColumn
{
    public OptionalDropdownColumn()
        : base(new PropertyCell())
    {
    }

    public override DataGridViewCell CellTemplate
    {
        get
        {
            return base.CellTemplate;
        }
        set
        {
            // Ensure that the cell used for the template is a PropertyCell.
            if (value != null &&
                !value.GetType().IsAssignableFrom(typeof(PropertyCell)))
            {
                throw new InvalidCastException("Must be a PropertyCell");
            }
            base.CellTemplate = value;
        }
    }
}

// And the corresponding Cell type
public class OptionalDropdownCell : DataGridViewTextBoxCell
{

    public OptionalDropdownCell()
        : base()
    {           
    }

    public override void InitializeEditingControl(int rowIndex, object
        initialFormattedValue, DataGridViewCellStyle dataGridViewCellStyle)
    {
        // Set the value of the editing control to the current cell value.
        base.InitializeEditingControl(rowIndex, initialFormattedValue,
            dataGridViewCellStyle);

        DataItem dataItem = (DataItem) this.OwningRow.DataBoundItem;
        if (dataItem.useCombo)
        {
            DataGridViewComboBoxEditingControl ctl = (DataGridViewComboBoxEditingControl)DataGridView.EditingControl;
            ctl.DataSource = dataItem.allowedItems;
            ctl.DropDownStyle = ComboBoxStyle.DropDownList;
        }
        else
        {
            DataGridViewTextBoxEditingControl ctl = (DataGridViewTextBoxEditingControl)DataGridView.EditingControl;
            ctl.Text = this.Value.ToString();
        }
    }

    public override Type EditType
    {
        get
        {
            DataItem dataItem = (DataItem)this.OwningRow.DataBoundItem;
            if (dataItem.useCombo)
            {
                return typeof(DataGridViewComboBoxEditingControl);
            }
            else
            {
                return typeof(DataGridViewTextBoxEditingControl);
            }
        }
    }
}

Then just add a column to your DataGridView of this type, and the correct edit control should be used.