[Solved] ASP.Net GridView SortExpression is not working

Sir good morning

My sort expression is not working in GridView, please help

<%-- Start Generator List --%>
<div class="container mb-0 mt-0" style="font-size: 12px; font-family: Arial;">
    <asp:Panel ID="PnlGenList" runat="server">
        <div class="row g-0 pt-0 " style="">
            <div class="col col-12 justify-content-center">
                <asp:GridView ID="GvGenList" runat="server"
                    GridLines="Both"
                    EmptyDataText="No Record Found"
                    EmptyDataRowStyle-ForeColor="Red"
                    EmptyDataRowStyle-Font-Bold="true"
                    EmptyDataRowStyle-BorderStyle="None"
                    CssClass=" MyDataGridViewListOne"
                    HorizontalAlign="Center"
                    AllowSorting="true"
                    OnSorting="OnSorting"
                    RowStyle-CssClass="rows"
                    AutoGenerateColumns="false">
                    <EmptyDataRowStyle BorderStyle="None" Font-Bold="True" ForeColor="Red"></EmptyDataRowStyle>
                    <FooterStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
                    <RowStyle CssClass="rows"></RowStyle>
                    <Columns>

                        <asp:TemplateField HeaderText="Sr.No" ItemStyle-Width="30" ItemStyle-HorizontalAlign="Left">
                            <ItemTemplate>
                                <asp:Label ID="lblRowNumber" Text='<%# Container.DataItemIndex + 1 %>' runat="server" />
                            </ItemTemplate>
                        </asp:TemplateField>

                        <%-- <asp:TemplateField ItemStyle-HorizontalAlign="Center" HeaderText="Select">
                            <ItemTemplate>
                            <asp:LinkButton ID="LnkSelectCustomer" runat="server" Text="Select" OnClick="ViewInvoiceDetail" ForeColor="Blue" Font-Size="14px" Font-Bold="true"
                            CommandArgument='<%# Eval("CustomerCode") + ";" + Eval("RegNo") + ";" + Eval("ModelCode") + ";" + Eval("CustomerCode") + ";" + Eval("NetAmount") + ";" + Eval("Paid") + ";" + Eval("Balance") + ";" + Eval("JobNoDetail") + ";" + Eval("InvoiceDate") %>'></asp:LinkButton>
                            </ItemTemplate>
                            </asp:TemplateField>--%>

                        <asp:TemplateField ItemStyle-HorizontalAlign="Center" HeaderText="Select">
                            <ItemTemplate>
                                <asp:LinkButton ID="LnkSelectCustomer" runat="server" Text="Select" OnClick="ViewGenDetail" ForeColor="Blue" Font-Size="14px" Font-Bold="true"
                                    CommandArgument='<%# Eval("GenCode") + ";" + Eval("GenName") %>'></asp:LinkButton>
                            </ItemTemplate>
                        </asp:TemplateField>

                        <asp:BoundField DataField="GenCode"
                            HeaderText="Gen Code"
                            SortExpression="GenCode"
                            ItemStyle-Wrap="False"></asp:BoundField>
                        <asp:BoundField DataField="GenName"
                            HeaderText="Gen Name"
                            SortExpression="GenName"
                            ItemStyle-Wrap="False"></asp:BoundField>
                        <asp:BoundField DataField="KVA"
                            HeaderText="KVA"
                            SortExpression="KVA"
                            ItemStyle-Wrap="False"></asp:BoundField>
                        <asp:BoundField DataField="ManualCode"
                            HeaderText="Manual Code"
                            ItemStyle-Wrap="False"></asp:BoundField>
                        <asp:BoundField DataField="Make"
                            HeaderText="Make"
                            SortExpression="Make"
                            ItemStyle-Wrap="False"></asp:BoundField>
                        <asp:BoundField DataField="EngineNo"
                            HeaderText="Engine No"
                            SortExpression="EngineNo"
                            ItemStyle-Wrap="False"></asp:BoundField>
                        <asp:BoundField DataField="AltSerialNo"
                            HeaderText="Alternator No"
                            ItemStyle-Wrap="False"></asp:BoundField>
                        <asp:BoundField DataField="SoundType"
                            HeaderText="Sound Type"
                            ItemStyle-Wrap="False"></asp:BoundField>
                        <asp:BoundField DataField="Health"
                            HeaderText="Health"
                            ItemStyle-Wrap="False"></asp:BoundField>
                        <asp:BoundField DataField="ActiveStatus"
                            HeaderText="Active" Visible="false"
                            ItemStyle-Wrap="False"></asp:BoundField>
                        <asp:BoundField DataField="AllocationStatus"
                            HeaderText="Allocated"
                            Visible="false"
                            ItemStyle-Wrap="False"></asp:BoundField>
                        <asp:BoundField DataField="LastReading"
                            HeaderText="Last Reading" ItemStyle-HorizontalAlign="Right"
                            Visible="false"
                            ItemStyle-Wrap="False"></asp:BoundField>
                    </Columns>
                </asp:GridView>
            </div>
        </div>

    </asp:Panel>
    <br />
    <br />
</div>
<%-- End Generator List --%>

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

public partial class GeneratorEntry : System.Web.UI.Page
{
    SqlConnection SqlCn;
    SqlCommand SqlCm;
    SqlDataReader SqlDr;
    SqlDataAdapter SqlDa;
    DataTable SqlDt;
    DataSet SqlDs;
    ConnectionState ConState;

    static string SqlQry;
    static string ConPath;
    static Boolean SmtpContectionStatus;

    // End Connection
    private string SortDirection
    {
        get { return ViewState["SortDirection"] != null ? ViewState["SortDirection"].ToString() : "ASC"; }
        set { ViewState["SortDirection"] = value; }
    }
    protected void OnSorting(object sender, GridViewSortEventArgs e)
    {
        this.LoadGenList(e.SortExpression);
    }
   
    protected void LoadGenList(string sortExpression = null)
    {
        ConnectionStringFunction();
        SqlCn = new SqlConnection(ConPath);
        SqlCn.Open();
        MainClass.ProcNameClass = "GeneratorList";

        try
        {
            SqlCm = new SqlCommand(MainClass.ProcNameClass, SqlCn);
            SqlCm.CommandType = CommandType.StoredProcedure;

            SqlCm.Parameters.AddWithValue("Action", ActionForProcess);
            SqlCm.Parameters.AddWithValue("GenCode", TxtSearchValue.Text.Trim().ToUpper());
            SqlCm.Parameters.AddWithValue("AltNo", TxtSearchValue.Text.Trim().ToUpper());
            SqlCm.Parameters.AddWithValue("EngineNo", TxtSearchValue.Text.Trim().ToUpper());
            SqlDa = new SqlDataAdapter();
            SqlDa.SelectCommand = SqlCm;
            SqlDt = new DataTable();
            SqlDa.Fill(SqlDt);

            if (sortExpression != null)
            {
                DataView dv = SqlDt.AsDataView();
                this.SortDirection = this.SortDirection == "ASC" ? "DESC" : "ASC";

                dv.Sort = sortExpression + " " + this.SortDirection;
                GvGenList.DataSource = dv;
            }
            else
            {
                GvGenList.DataSource = SqlDt;
            }

            GvGenList.DataBind();

            TotalRowCount = GvGenList.Rows.Count;
            TotalColCount = GvGenList.Columns.Count;
            if (TotalRowCount == 0)
            {
                GvGenList.Visible = false;
                ClientScript.RegisterClientScriptBlock(this.GetType(), "alert",
                "swal('Warning!','No Record Found' , 'warning')", true);
                return;
            }
            GvGenList.Visible = true;

            //for (int i = 0; i <= TotalColumnCount - 1; i++)
            //{
            // GvStaffList.Columns[i].ItemStyle.Wrap = false;
            //}
        }
        // End Try
        catch (Exception ex)
        {
            TransactionStatus = false;
        }
        // Catch

        finally
        {
            SqlCn.Close();
        }
        // End Finally

    }
    // End Load Gen List
}