汇总DataGridView中某些列的值

Question

I have a simple dataGridView with 4 columns. I want to sum up values from a third column and save the result into variable on button press. I tried like this, but I always get an error saying

"Specified cast is not valid - when casting from a number, the value must be less than infinity".

PS Each cell is bassically a DataGridViewTextBoxColumn, meaning I can input values directly.

Code:

private void button2_Click(object sender, EventArgs e)
    {
        Double result = 0;
        foreach (DataGridViewRow row in this.dataGridView1.Rows)
        {
            result += (Double)row.Cells[2].Value;
        }

        this.label13.Text = result .ToString();
    }

What am I missing?

Answer 1

Rather than casting, try

result += Convert.ToDouble(row.Cells[2].Value);

With error checking

if (row.Cells[2].Value != null)
{
    try
    {
        result += Convert.ToDouble(row.Cells[2].Value);
    }
    catch { }
}

Answer 2

DataTable dt =DataGridView1.DataSource as DataTable;

decimal total;

total=(int)dt.Compute("sum(column_name)","");

Answer 3

private getColSum()
{
    int sum = 0;
    for (int i = 0; i < dataGridView1.Rows.Count; ++i)
    {
        sum += Convert.ToInt32(dataGridView1.Rows[i].Cells[2].Value);
    }
    return sum;
}