Reset Ultragrid or datagrid view

I don't know anything about the UltraGrid but as far as the DataGridView is concerned:

1. If it's data-bound (as they usually are), then set its DataSource property to null.

2. If it's not data-bound but, after clearing, you still want to allow the user to enter new rows, then call its Rows.Clear() method.

3. If it's not data-bound and, after clearing, you don't want to allow the user to add any new rows, then set its AllowUserToAddRows property to false and either call Rows.Clear() or set the RowCount property to 0.