hola ,eso lo podrias hacer en el RowDataBound de tu gridview:
string variable1,variable2,variable3, etc;
protected void gridview_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
variable1 = e.Row.Cells[0].ToString();
variable2 = e.Row.Cells[1].ToString();
variable3 = e.Row.Cells[2].ToString();
}
}
espero que te sirva