Auto sum Column accumulated value in gridview

Question

The principle seems simple but I'm in trouble. Did anyone have an example or script to auto sum of a column in the gridview. Explain, I have a gridview with the columns:
amount, unitary value, total value and accumulated value. I need the accumulated value column add the previous value
to the current value. For example:
quantity unitary_value total_value accumulated_value
10 10,00 100,00 100,00
20 50,00 1.000,00 1.100,00
5 500,00 2.500,00 3.600,00
Basically it would be up. The column value (accumulated value) takes the value of the previous line and adds to the current value.
If you can help !!
Thank you for your attention.
Thank you for your attention.

Answer 1

No you're right with the calculation of the first post, I got it wrong. Now check the below solution, you need to use RowDataBound event of the gridview to do the calculation and print in the cell:
//This is just a method to fill the datatable with dummy data(you can ignore in your code)static DataTable GetTable()
// Here we create a DataTable with four columns.
DataTable table = new DataTable();
table.Columns.Add("quantity", typeof(double));
table.Columns.Add("unitary_value", typeof(double));
table.Columns.Add("total_value", typeof(double));
table.Columns.Add("accumulated_value", typeof(double));
// Here we add five DataRows.
table.Rows.Add(10, 10, 0, 0);
table.Rows.Add(20, 50, 0, 0);
table.Rows.Add(30, 40, 0, 0);
return table;
protected void Page_Load(object sender, EventArgs e)
//Bind the gridview to the datatable
GridView1.DataSource = GetTable();
GridView1.DataBind();
//Global var to keep accumulated value of each rowo
double _accumulatedvalue = 0;
protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
if (e.Row.RowType == DataControlRowType.DataRow)
//Create total value column by multiplying cells 1 and 2(maybe you don't need this)
Double val = Convert.ToDouble(e.Row.Cells[0].Text) * Convert.ToDouble(e.Row.Cells[1].Text);
e.Row.Cells[2].Text = val.ToString();
//Accumualated value and fill the cell related (you can replace val below with Convert.ToDouble(e.Row.Cells[2].Text)
_accumulatedvalue = _accumulatedvalue + val;
e.Row.Cells[3].Text = _accumulatedvalue.ToString();
Fouad Roumieh