Hi John,

In fact, the editing control hosted in a DataGridViewTextBoxCell is a
standard TextBox. We can retrieve the hosted TextBox and then set its
AutoCompleteMode and AutoCompleteSource properties to get what you want.

To get the hosted editing control in a DataGridViewCell, we could handle
the EditingControlShowing event of the DataGridView. The following is a
sample.

void dataGridView1_EditingControlShowing(object sender,
DataGridViewEditingControlShowingEventArgs e)
 {
           TextBox txtbox = e.Control as TextBox;
           if (txtbox != null)
           {
               txtbox.AutoCompleteMode = AutoCompleteMode.Suggest;
               txtbox.AutoCompleteSource = AutoCompleteSource.FileSystem;
           }
 }

Please try it out and let me know the result.

If you have any question, feel free to tell me.

Sincerely,
Linda Liu
Microsoft Online Community Support

==================================================
Get notification to my posts through email? Please refer to
http://msdn.microsoft.com/subscriptions/managednewsgroups/default.aspx#notif
ications.

Note: The MSDN Managed Newsgroup support offering is for non-urgent issues
where an initial response from the community or a Microsoft Support
Engineer within 1 business day is acceptable. Please note that each follow
up response may take approximately 2 business days as the support
professional working with you may need further investigation to reach the
most efficient resolution. The offering is not appropriate for situations
that require urgent, real-time or phone-based interactions or complex
project analysis and dump analysis issues. Issues of this nature are best
handled working with a dedicated Microsoft Support Engineer by contacting
Microsoft Customer Support Services (CSS) at
http://msdn.microsoft.com/subscriptions/support/default.aspx.
==================================================

This posting is provided "AS IS" with no warranties, and confers no rights.