Sum of GridView Column using Row Cells

Question

I am trying to find the sum of all the cells of a column in my gridview. However I am getting the error:

I am trying to calculate the entire column and throw it in a label outside of the gridview.

The output from Row.Cells[4] is 459.00

Input string was not in a correct format.

on line: Line 509: sum += Decimal.Parse(c.Text);

Here is my code:

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.DataItem != null)
    {
        // Set the capacity label text
        Label4.Text = e.Row.Cells[4].Text;


        // Calc the sum of all of the row values
        decimal sum = 0;
        foreach (TableCell c in e.Row.Cells)
        {
            sum += Decimal.Parse(c.Text);
        }


        // Set the sum label text value
        Label5.Text = sum.ToString();
    }
}

Answer 1

Make the sum a global variable.

decimal sum = 0;

then for each row add to the global variable:

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow && e.Row.DataItem != null)
    {
        // Set the capacity label text

        sum += Decimal.Parse(e.Row.Cells[4].Text);

    }
}

then in the page_prerender put the following:

// Set the sum label text value
Label5.Text = sum.ToString();

Answer 2

You also may want to check that Row.ItemType is an item, not the header. Also, it's safer to do:

decimal val;

foreach (..)
{
//only call Trim() if you know the text is not null.
If (Not Decimal.TryParse(c.Text.Trim()), out val) {
   //error condition; you can throw an exception just for testing to verify something is or isn't right
   throw new Exception("Error, field is not a decimal: " + c.Text);
}
else { 
    sum += val;
}

Also, any totalling has to be done outside of the ItemDataBound event too. So Setting the total to a label isn't the right time for that.