C# Gridview CheckBox Field VS (Template Field + CheckBox)

I got a gridview that pulls out a column of "Product" from the database.

With that, I would need a checkbox for the user to "checked" against each product in the gridview when it's finished.

I have research about CheckBox Field VS (Template Field + CheckBox) and decided to use (Template Field + CheckBox) for the gridview to hold the checkbox.

GridView Column[0] = Product Name GridView Column [1] = Checkbox

After "checking" some checkboxes, then the user click submit which would trigger the event below.

string checkedBy;        
foreach (GridViewRow row in grvCheckList.Rows)
{
   // Im not sure how to check if each checkbox has been "checked" 
   // or not as it is in the gridview  cell.

   // what I like to have is
      if((checkbox in column[1]).checked == true)
      { 
        checkedBy = // Staff name 
        // my codes to store the staff name into database with respective to the product listed in             the gridview row 
       }
      else
      { 
        checkedBy = "NULL"
        // my code to store "NULL" into database with respect to the product listed in the gridview        row
      }
}   

For usual checkbox, what I normally do is below

if(checkbox1.checked == true ) 
else if(checkbox2.checked == true )
else if(checkbox3.checked == true )
etc

So the my question is how do I check if the checkbox in each row has been "checked" or not despite every row in the gridview uses the same checkbox.