如何实现dropdownedit DevExpress控件？

Question

当我尝试在我的项目中实现DropDownEditor Control时，我遇到了问题。

这是网站中的示例代码点击here

这是我的代码：

<asp:ObjectDataSource ID="ObjectDataSource1" runat="server" SelectMethod="Listar" TypeName="AlsaGroup.Alsa.AlsaWeb.BusinessLogic.ServicioBL" InsertMethod="Agregar">
                <InsertParameters>
                    <asp:Parameter Name="nombreServicio" Type="String" />
                </InsertParameters>
            </asp:ObjectDataSource>
            <dx:ASPxDropDownEdit ID="DDLEditServicio" runat="server" ClientInstanceName="DDLEditServicio"
                Width="170px" AllowUserInput="False" AnimationType="None">
                <DropDownWindowStyle>
                    <Border BorderWidth="0px" />
                </DropDownWindowStyle>
                <DropDownWindowTemplate>
                    <dx:ASPxGridView ID="GridView" runat="server" AutoGenerateColumns="False" ClientInstanceName="GridView"
                        Width="500px" DataSourceID="ObjectDataSource1" KeyFieldName="Cod_Serv" OnRowInserting="GridView_RowInserting"
                        OnInitNewRow="GridView_InitNewRow" OnCustomJSProperties="GridView_CustomJSProperties"
                        OnAfterPerformCallback="GridView_AfterPerformCallback">
                        <Columns>
                            <dx:GridViewCommandColumn VisibleIndex="0">
                                <NewButton Visible="True">
                                </NewButton>
                            </dx:GridViewCommandColumn>
                            <dx:GridViewDataTextColumn FieldName="Cod_Serv" VisibleIndex="1" ReadOnly="True" Caption="Cod. Serv.">
                                <EditFormSettings Visible="False" />
                            </dx:GridViewDataTextColumn>
                            <dx:GridViewDataTextColumn FieldName="Des_Serv" VisibleIndex="2" Caption="Descripcion ">
                            </dx:GridViewDataTextColumn>
                        </Columns>
                        <ClientSideEvents Init="GridViewInitHandler" RowClick="RowClickHandler" EndCallback="EndCallbackHandler" />
                        <Settings VerticalScrollBarMode="Visible" />
                        <SettingsBehavior ConfirmDelete="True" EnableRowHotTrack="True" AllowFocusedRow="True" />
                        <SettingsPager Mode="ShowAllRecords" />
                    </dx:ASPxGridView>
                </DropDownWindowTemplate>
            </dx:ASPxDropDownEdit>

这是C＃中的代码：

    protected void GridView_RowInserting(object sender, DevExpress.Web.Data.ASPxDataInsertingEventArgs e)
    {
        var grid = sender as ASPxGridView;

        //e.NewValues["Cod_Serv"] = AlsaGroup.Alsa.AlsaWeb.BusinessLogic.ServicioBL.Instancia.Agregar("xxx")
        //e.NewValues["ID"] = EmployeeSessionProvider.GenerateNewID();

    }   

    protected void GridView_AfterPerformCallback(object sender, DevExpress.Web.ASPxGridView.ASPxGridViewAfterPerformCallbackEventArgs e)
    {
        SynchronizeFocusedRow();
    }

    private void SynchronizeFocusedRow()
    {
        var grid = (ASPxGridView)DDLEditServicio.FindControl("GridView");
        var lookupKeyValue = DDLEditServicio.KeyValue;
        grid.FocusedRowIndex = grid.FindVisibleIndexByKeyValue(lookupKeyValue);
    }

    protected void GridView_InitNewRow(object sender, DevExpress.Web.Data.ASPxDataInitNewRowEventArgs e)
    {
        var grid = sender as ASPxGridView;
        if (grid != null) grid.ScrollToVisibleIndexOnClient = 0;
    }

    protected void GridView_CustomJSProperties(object sender, DevExpress.Web.ASPxGridView.ASPxGridViewClientJSPropertiesEventArgs e)
    {
        var grid = (ASPxGridView)DDLEditServicio.FindControl("GridView");
        var servicioLista = new object[grid.VisibleRowCount];
        var keyValues = new object[grid.VisibleRowCount];
        for (var i = 0; i < grid.VisibleRowCount; i++)
        {
            servicioLista[i] = grid.GetRowValues(i, "Des_Serv"); //+ " " + grid.GetRowValues(i, "LastName");
            keyValues[i] = grid.GetRowValues(i, "Cod_Serv");
        }
        e.Properties["cpDes_Serv"] = servicioLista;
        e.Properties["cpCod_Serv"] = keyValues;
    }

我的问题是在插入新值的事件中，在示例中我看到一个新事件NewGenerateID（），我怎么有一个方法在插入数据时返回一个新值，但我需要一个ParameterValue。

我配置了一个ObjectDataSource，它映射了要插入和选择的方法，出了什么问题？