Hi Randy,
When a cell is not being edited, its conent is painted with the
corresponding DataGridColumnStyle's Paint method (there are several
overloads). When it is being edited, cell appearence is in hands of a user
control used to edit the cell contents - most likely this will be a TextBox.
So what you need is inheriting from
System.Windows.Forms.DataGridTextBoxColumn and overriding its Paint method
to enable wrapping. You might also need to overload column style methods
responsible for calculating the row height - the grid won't be able to
adjust the row height upon double-click between row headers otherwise. To
make the text wrap during editing, you will need to tweak the hosted
TextBox - probably it should be switched to the MultiLine mode, but I am not
so sure here.