If the user enters data into the new row template, a new row is automatically added to the grid.
This property works in bound mode (if the data source supports adding new rows) and also in unbound mode.
Note that if this property is set to true, the Rows.Count property will return a value that includes the new row template. If you set the Rows.Count property, the grid will set the number of data rows and will automatically add the new row template. For example:
flex.AllowAddNew = true; flex.Rows.Count = 10; Console.WriteLine("Row count is {0}.", _flex.Rows.Count); Row count is 11.