有人用过ListView和ObjectDataSource配合的删除功能吗？ObjectDataSource的DeleteParameters的参数怎么指定

<asp:ListView ID="ListView1" runat="server" DataSourceID="ObjectDataSource1" DataKeyNames="FunctionID">
        <ItemTemplate>
略……
</asp:ListView><asp:ObjectDataSource ID="ObjectDataSource1" runat="server" TypeName="Wsb.BLL.Function" SelectMethod="GetFunctionTree" DeleteMethod="Delete">
        <DeleteParameters>
            <asp:ControlParameter ControlID="ListView1" Name="FunctionID" Type="Int32" PropertyName="DataKeyNames" />
        </DeleteParameters>
    </asp:ObjectDataSource>
这样做，会发生：对象必须实现 IConvertible的错误，请问怎么解决？