ASP.NET

<asp:TemplateField HeaderText="Nome" SortExpression="Nome">
                                <EditItemTemplate>
                                    <asp:TextBox ID="txtname" runat="server" Text='<%# Bind("Name") %>'></asp:TextBox>
                                </EditItemTemplate>
                                <ItemTemplate>
                                    <asp:Label ID="lblname" runat="server" Text='<%# Bind("Name") %>'></asp:Label>
                                </ItemTemplate>
                                <FooterTemplate>
                        <asp:TextBox ID="txtNName" runat="server" width="75px" Visible='<%# (bool) show_hide_insert() %>'> </asp:TextBox>
                    </FooterTemplate>
                            </asp:TemplateField>

public void TempTable()
    {
        DataTable dt = new DataTable();
        dt.Columns.Add("ID", typeof(int));
        dt.Columns.Add("Name", typeof(String));
        dt.Columns.Add("Year", typeof(String));

// i've erased some colummns here

        dt.Columns.Add("Image", typeof(String));



        Session["data"] = dt;
        Temp = dt.Copy();
      
// query. ...

        DataSet ds = GetData(query);
        GridView3.DataSource = ds;
        GridView3.DataBind();

    }

DataSet GetData(String queryString)
    {

        string connectionString;
        connectionString = WebConfigurationManager.ConnectionStrings["ConnectionString1"].ConnectionString;
        DataSet ds = new DataSet();

        try
        {
         
            SqlConnection Conn = new SqlConnection(connectionString);
            SqlDataAdapter adapter = new SqlDataAdapter(queryString, connectionString);
            adapter.Fill(ds);

        }
        catch (Exception ex)
        {
            Response.Write(ex.Message);

        }

        return ds;
    }

public DataTable Temp
    {
        get
        {
            object o = ViewState["Temp"];
            if (o == null)
            {
                DataTable dt = new DataTable();
                return dt;
            }
            else
                return (DataTable)o;
        }
        set
        {
            ViewState["Temp"] = value;
        }
    }

private string ConvertSortDirectionToSql(SortDirection sortDirection)
    {
        string newSortDirection = String.Empty;

        switch (sortDirection)
        {
            case SortDirection.Ascending:
                newSortDirection = "ASC";
                break;

            case SortDirection.Descending:
                newSortDirection = "DESC";
                break;
        }

        return newSortDirection;
    }

    protected void GridView3_PageIndexChanging(object sender, GridViewPageEventArgs e)
    {
        
        GridView3.PageIndex = e.NewPageIndex;
        GridView3.DataBind();
    }

    protected void GridView3_Sorting(object sender, GridViewSortEventArgs e)
    {
        DataTable dataTable = GridView3.DataSource as DataTable;

        if (dataTable != null)
        {
            DataView dataView = new DataView(dataTable);
            dataView.Sort = e.SortExpression + " " + ConvertSortDirectionToSql(e.SortDirection);

            GridView3.DataSource = dataView;
            GridView3.DataBind();
        }
    }