title: How does one sum a whole column of datagridview?
body: <p>I have a Datagridview in my C# program that contain numeric data.</p>
  
  <p>I need to sum all column A  and all column B.</p>
  
  <p>(I don't want to use any SQL queries.)</p>
  
  <p>How Do I do this?</p>
  
  <p>Thanks in advance.</p>