WMI .NET无效查询

Question

尝试执行以下查询时,我不断收到"无效查询"异常:

ManagementObjectSearcher searcher = new ManagementObjectSearcher("SELECT * FROM Win32_DiskQuota WHERE QuotaVolume.DeviceID = 'C:'");
ManagementObjectCollection quotaCollection = searcher.Get();

但是这可行:"SELECT*FROM Win32_DiskQuota".

根据MSDN:

对于WHERE子句中类描述符的大多数用法,WMI将查询标记为无效并返回错误.但是,对WMI中的object类型的属性使用点(.)运算符.例如,如果Prop是MyClass的有效属性并且类型为object,则以下查询有效:

SELECT*FROM MyClass WHERE Prop.embedprop = 5

这是否意味着只有在Prop宣布为OBJECT时才有效？

以下是异常详细信息:

System.Management.ManagementException was unhandled
  HResult=-2146233087
  Message=Invalid query 
  Source=System.Management
  StackTrace:
       ? System.Management.ManagementException.ThrowWithExtendedInfo(ManagementStatus errorCode)
       ? System.Management.ManagementObjectCollection.ManagementObjectEnumerator.MoveNext()
       ? UserQuota.Program.getQuota() ? c:\users\administrator\documents\visual studio 2015\Projects\UserQuota\UserQuota\Program.cs:?????? 40
       ? UserQuota.Program.Main(String[] args) ? c:\users\administrator\documents\visual studio 2015\Projects\UserQuota\UserQuota\Program.cs:?????? 33
       ? System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       ? System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       ? Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       ? System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       ? System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       ? System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       ? System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       ? System.Threading.ThreadHelper.ThreadStart()
  InnerException: 

Answer 1

是的。根据Win32_DiskQuota 类文档，QuotaVolume 属性是对 Win32_LogicalDisk WMI 类的引用。您提供的 MSDN 报价给出了根据 WQL 规范查询无效的原因。

相反，你可以使用这样的东西：

ManagementObjectSearcher searcher = new ManagementObjectSearcher("SELECT * FROM Win32_DiskQuota WHERE QuotaVolume = \"Win32_LogicalDisk.DeviceID=\\\"C:\\\"\"");
ManagementObjectCollection quotaCollection = searcher.Get();

（注意所有的逃逸......）