[技术讨论] WMI中限定符的疑问

czjt1234

Set objSWbemLocator = CreateObject("WbemScripting.SWbemLocator")
Set objSWbemServices = objSWbemLocator.ConnectServer()
Set objSWbemObject = objSWbemServices.Get("win32_service")
Set objSWbemQualifierSet = objSWbemObject.Properties_.Item("CreationClassName").Qualifiers_
strQualifier = "该类的限定符的个数：" & objSWbemQualifierSet.Count & vbCrLf & vbCrLf
For Each objSWbemQualifier In objSWbemQualifierSet
    strQualifier = strQualifier & objSWbemQualifier.Name & vbCrLf
Next
Msgbox strQualifier
Msgbox "cim_key限定符的值：" & objSWbemQualifierSet.Item("cim_key").Value
复制代码

在http://msdn.microsoft.com/en-us/library/aa393650.aspx中没有cim_key这个限定符类型啊？

还有http://msdn.microsoft.com/en-us/library/windows/desktop/aa394418(v=vs.85).aspx里
说CreationClassName属性
CreationClassName
Data type: string
Access type: Read-only
Qualifiers: MaxLen (256)
有限定符MaxLen，但上述代码里并没有显示，什么原因？