asp.net - GridView の整数列が文字列として並べ替えられている

Question

GridView以下に示すような列を持つ があります。

<asp:TemplateField HeaderText="Vendor Path" SortExpression="DocumentTemplateFieldID" ItemStyle-HorizontalAlign="Center" HeaderStyle-HorizontalAlign="Center">
    <ItemTemplate>
        <asp:Label ID="vendor" Height="10px" Width="60px" runat="server" Text='<%# Eval("DocumentTemplateFieldID") %>'> </asp:Label>
    </ItemTemplate>
</asp:TemplateField>

並べ替えを許可します。ただし、文字列であるかのように並べ替えます。データベースでは、整数列です。

GridView本当にそこに整数を入れていることを受け入れるにはどうすればよいですか? 私はそれを変換しようとしましたが、うまくいきませんでした。

追加されたコード:

Protected Sub TaskGridView_Sorting(ByVal sender As Object, ByVal e As GridViewSortEventArgs) Handles GridView1.Sorting
    dsData = Session("dataTableView")
    Dim sortExpression As String = e.SortExpression
    Dim direction As String = String.Empty
    If SortDirection = SortDirection.Ascending Then
        SortDirection = SortDirection.Descending
        direction = " DESC"
    Else
        SortDirection = SortDirection.Ascending
        direction = " ASC"
    End If
    Dim table As DataTable = dsData
    table.DefaultView.Sort = sortExpression + direction
    GridView1.DataSource = table
    GridView1.DataBind()
    Session("dataTableView") = table
End Sub
Private Property SortDirection() As SortDirection
    Get
        If Session("sortDir") = Nothing Then
            Session("sortDir") = SortDirection.Ascending
        End If

        Return CType(Session("sortDir"), SortDirection)
    End Get

    Set(ByVal value As SortDirection)
        Session("sortDir") = value
    End Set

End Property

更新しました：

Public Function initialQuery(ByVal vendorID As String) As DataTable
    Dim objConn As IDbConnection = Nothing
    Dim dsData As New DataTable
    Dim objParams(0) As IDbDataParameter
    Try
        objConn = DBAccess.GetConnection
        objParams(0) = DBAccess.CreateParameter("DWSVendorID", DbType.String, vendorID, ParameterDirection.Input)
        'Need to figure out how to add the below code:
        If (Not IsNothing(vendorID) And Not vendorID = 0) Then

            '      strBlder.Append("WHERE B.DocumentProviderID = '" + vendorID.ToString + "' ")
        End If
        dsData = DBAccess.ExecuteDataTable(objConn, DataAccessHelper.Schema & "LLC.[DWSMappingToolInitialQuery]", objParams)

    Finally
        If Not objConn Is Nothing Then
            DBAccess.CloseConnection(objConn)
        End If
    End Try
    If dsData.Rows.Count > 0 Then
        Return dsData
    End If

    Return Nothing
End Function