Hi jmontano,

Refer below link.

Display sum of ASP.Net GridView column total with paging and filtering using C# and VB.Net

Hi jmontano,

Check this sample and take its reference.

HTML

<asp:GridView runat="server" ID="gvOrders" AutoGenerateColumns="false" OnPageIndexChanging="gvOrders_PageIndexChanging"
    AllowPaging="true" PageSize="10" ShowFooter="true">
    <Columns>
        <asp:BoundField DataField="OrderID" HeaderText="Order ID" />
        <asp:BoundField DataField="ProductName" HeaderText="Product Name" />
        <asp:BoundField DataField="Price" HeaderText="Price" DataFormatString="{0:N2}" />
    </Columns>
</asp:GridView>

Namespaces

C#

using System.Configuration;
using System.Data;
using System.Data.SqlClient;

VB.Net

Imports System.Configuration
Imports System.Data
Imports System.Data.SqlClient

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        this.BindOrders();
    }
}

private void BindOrders()
{
    using (SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["constr"].ConnectionString))
    {
        string query = "SELECT TOP 50 OrderID,";
        query += "(SELECT ProductName FROM Products WHERE ProductID = [Order Details].ProductID) ProductName,";
        query += "(UnitPrice * Quantity) Price ";
        query += "FROM [Order Details] ";
        using (SqlCommand cmd = new SqlCommand(query, con))
        {
            cmd.CommandType = CommandType.Text;
            using (SqlDataAdapter sda = new SqlDataAdapter())
            {
                sda.SelectCommand = cmd;
                DataTable dt = new DataTable();
                sda.Fill(dt);
                this.gvOrders.DataSource = dt;
                this.gvOrders.DataBind();

                decimal total = 0;
                foreach (GridViewRow row in gvOrders.Rows)
                {
                    decimal price = Convert.ToDecimal(row.Cells[2].Text);
                    total += price;
                }
                gvOrders.FooterRow.Cells[1].Text = "Total";
                gvOrders.FooterRow.Cells[1].HorizontalAlign = HorizontalAlign.Right;
                gvOrders.FooterRow.Cells[2].Text = total.ToString();
            }
        }
    }
}

protected void gvOrders_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
    this.gvOrders.PageIndex = e.NewPageIndex;
    this.BindOrders();
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Me.BindOrders()
    End If
End Sub

Private Sub BindOrders()
    Using con As SqlConnection = New SqlConnection(ConfigurationManager.ConnectionStrings("constr").ConnectionString)
        Dim query As String = "SELECT TOP 50 OrderID,"
        query += "(SELECT ProductName FROM Products WHERE ProductID = [Order Details].ProductID) ProductName,"
        query += "(UnitPrice * Quantity) Price "
        query += "FROM [Order Details] "
        Using cmd As SqlCommand = New SqlCommand(query, con)
            cmd.CommandType = CommandType.Text
            Using sda As SqlDataAdapter = New SqlDataAdapter()
                sda.SelectCommand = cmd
                Dim dt As DataTable = New DataTable()
                sda.Fill(dt)
                Me.gvOrders.DataSource = dt
                Me.gvOrders.DataBind()
                Dim total As Decimal = 0
                For Each row As GridViewRow In gvOrders.Rows
                    Dim price As Decimal = Convert.ToDecimal(row.Cells(2).Text)
                    total += price
                Next
                gvOrders.FooterRow.Cells(1).Text = "Total"
                gvOrders.FooterRow.Cells(1).HorizontalAlign = HorizontalAlign.Right
                gvOrders.FooterRow.Cells(2).Text = total.ToString()
            End Using
        End Using
    End Using
End Sub

Protected Sub gvOrders_PageIndexChanging(ByVal sender As Object, ByVal e As GridViewPageEventArgs)
    Me.gvOrders.PageIndex = e.NewPageIndex
    Me.BindOrders()
End Sub

Screenshot