求助：关于ASPxgridview

ASPxGridView中 GridViewDataComboBoxColumn 怎么实现下拉 --------------------编程问答-------------------- 前台：<dxwgv:ASPxGridView ID="grid" ClientInstanceName="grid" KeyFieldName="keyid" OnCellEditorInitialize="grid_CellEditor"
        runat="server" DataSourceID="ObjectDataSource1" AutoGenerateColumns="False">
  <Columns>
     <dxwgv:GridViewDataTextColumn FieldName="keyid" Visible="false">
     </dxwgv:GridViewDataTextColumn>
     <dxwgv:GridViewDataTextColumn FieldName="name" Visible="true" Caption="省份" VisibleIndex="1">
     </dxwgv:GridViewDataTextColumn>
     <dxwgv:GridViewDataComboBoxColumn Caption="城市" FieldName="keyid" VisibleIndex="2">
     <PropertiesComboBox EnableIncrementalFiltering="true" EnableSynchronization="False" DropDownStyle="DropDown">
     </PropertiesComboBox>
     </dxwgv:GridViewDataComboBoxColumn>
     <dxwgv:GridViewDataTextColumn FieldName="description" Caption="描述" Visible="true" VisibleIndex="3">
     </dxwgv:GridViewDataTextColumn>
  </Columns>
</dxwgv:ASPxGridView>
    <asp:ObjectDataSource ID="ObjectDataSource1" runat="server"
        SelectMethod="Selectrole" TypeName="Traffic.Business.BusinessAspxGridView"></asp:ObjectDataSource>
后台：

string val = (string)grid.GetRowValuesByKeyValue(e.KeyValue, "keyid");
            ASPxComboBox com = e.Editor as ASPxComboBox;
            if (string.IsNullOrEmpty(val)) return;
            BusinessAspxGridView bus = new BusinessAspxGridView();
            List<string> editor = bus.Selectruser(val);
            foreach (string s in editor)
            {
                com.Items.Add(s);
            }
为什么下拉项没有出来呢？ --------------------编程问答-------------------- 大虾们帮下忙啦？来人看看撒 --------------------编程问答-------------------- --------------------编程问答-------------------- http://wenku.baidu.com/view/c6d6960f76c66137ee061920.html
提供一个相关资料的网页你去看下了.我也没操作过了,期待高手.......... --------------------编程问答-------------------- 你的KeyID有两个？去掉一个试试 --------------------编程问答-------------------- <dx:ASPxComboBox ID="ddlCJ" ClientInstanceName="ddlCJ" runat="server" ValueType="System.String"
                        Width="120px" TextField="JGMC" ValueField="JGBM">
                        <ClientSideEvents SelectedIndexChanged="function(s, e) {ddlQJZC.PerformCallback(s.GetValue().toString());}" />
                    </dx:ASPxComboBox> --------------------编程问答--------------------

引用 6 楼 zsyviolet 的回复:

<dx:ASPxComboBox ID="ddlCJ" ClientInstanceName="ddlCJ" runat="server" ValueType="System.String"
Width="120px" TextField="JGMC" ValueField="JGBM">
<ClientSideEvents SelectedIndexChanged="function……

在后台绑定一下就行了 --------------------编程问答-------------------- 下拉列也要设置一个DataSource吧

补充：.NET技术 ,  C#