想实现这么个功能，发现pb自带的例子中有这么一段
lcd_Object = FindClassDefinition(String(ltvi_Item.Data), is_LibraryList)
If IsNull(lcd_Object) Then
MessageBox("Error","Object Not Found.")
Return
End If
ll_Rows = UpperBound(lcd_Object.nestedclasslist)
原文：http://www.cnblogs.com/szxiaofei14/p/6006468.html