Yes, that's possible. Just add an edit button on your datagrid and mark this one as your default button. When you doubleclick on a row your edit form will be opened. The editable property in your dataview does not apply on datagrid within that dataview.
You could also set the editable property of a column in your datagrid. That way you can directly edit your rows in the datagrid. But I wouldn't prefer this method.