主题：[求助]请问代码哪里错了

.NET Framework 版本：2.0.50727.3053
Foxtable 版本：2014.9.2.1
错误所在事件：表，质量证明书，PrepareEdit
详细错误信息：
Exception has been thrown by the target of an invocation.
Items collection cannot be modified when the DataSource property is set.

PrepareEdit

Select Case e.Col.Name   
    Case "许可证编号","提货单位","执行标准","牌号","尺寸","长度","购货单位"
        e.Col.ComboList = DataTables("质量证明书").GetComboListString(e.Col.name)
End Select