Calculate ASP.Net GridView cell value from bottom to top using C# and VB.Net

Hi shal,

Please refer below sample.

HTML 

<asp:GridView ID="gvCalulation" AutoGenerateColumns="false" runat="server">
    <Columns>
        <asp:BoundField HeaderText="Process" DataField="Process" />
        <asp:BoundField HeaderText="%" DataField="%" />
        <asp:BoundField HeaderText="Value" DataField="Value" />
    </Columns>
</asp:GridView>

Namespace

C#

using System.Data;

VB.Net

Imports System.Data

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    DataTable dt = new DataTable();
    dt.Columns.AddRange(new DataColumn[] {
                            new DataColumn("Process"),
                            new DataColumn("%", typeof(int)),
                            new DataColumn("Value", typeof(int))
        });
    dt.Rows.Add("A", 99);
    dt.Rows.Add("B", 97);
    dt.Rows.Add("C", 99);
    for (int i = dt.Rows.Count - 1; i >= 0; i--)
    {
        DataRow dr = dt.Rows[i];
        if (i == dt.Rows.Count - 1)
        {
            dr["Value"] = (1000 / Convert.ToDecimal(dr["%"])) * 100;
        }
        else
        {
            dr["Value"] = (Convert.ToDecimal(dt.Rows[i + 1]["Value"]) / Convert.ToDecimal(dr["%"])) * 100;
        }
    }
    this.gvCalulation.DataSource = dt;
    this.gvCalulation.DataBind();
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    Dim dt As DataTable = New DataTable()
    dt.Columns.AddRange(New DataColumn() {New DataColumn("Process"), New DataColumn("%", GetType(Integer)), New DataColumn("Value", GetType(Integer))})
    dt.Rows.Add("A", 99)
    dt.Rows.Add("B", 97)
    dt.Rows.Add("C", 99)

    For i As Integer = dt.Rows.Count - 1 To 0 Step -1
        Dim dr As DataRow = dt.Rows(i)
        If i = dt.Rows.Count - 1 Then
            dr("Value") = (1000 / Convert.ToDecimal(dr("%"))) * 100
        Else
            dr("Value") = (Convert.ToDecimal(dt.Rows(i + 1)("Value")) / Convert.ToDecimal(dr("%"))) * 100
        End If
    Next

    Me.gvCalulation.DataSource = dt
    Me.gvCalulation.DataBind()
End Sub

Screenshot