ASP.NET - How to get gridview cells by cell name

The following line of code will get value form cell 12 in row 10

myDataGrid.Rows(10).Cells(12).Text

If I add new field (cell) to this datagrid, before cell 12, I will have to modify my code to

myDataGrid.Rows(10).Cells(13).Text

If there are many columns in the grid view, it might be very time consuming..

To get cells in datagrid by name,

1. Add column name to datakeynames 

Ensure it is the same is DataField in Fields screen

then replace 

myDataGrid.Rows(10).Cells(13).Text

with

myDataGrid.DataKeys(10).Values("id").ToString