Here's how to list WMI event classes in the root\cimv2 namespace with C# and System.Management:
using System;
using System.Management;
class Program
{
static void Main()
{
string query =
@"Select * From Meta_Class Where __This Isa '__Event'";
ManagementObjectSearcher searcher =
new ManagementObjectSearcher(query);
foreach (ManagementBaseObject cimv2Class in searcher.Get())
{
Console.WriteLine(cimv2Class.ClassPath.ClassName);
}
}
}
root\cimv2 is the default WMI namespace so you don't have to use a ManagementScope instance. The WQL query passed to ManagementObjectSearcher is a WMI metadata query. It uses "Meta_Class" to designate the query as a schema query, and "__This" property to recursively list __Event subclasses (see here and here).
WMI class is an event class if its provider implemented as an event WMI provider and must be a subclass of __Event. This doesn't mean that you can't use 'ordinary' WMI classes like Win32_Process and Win32_Service in WQL event queries. You just have to use one of the __InstanceOperationEvent derived helper classes like __InstanceCreationEvent or __InstanceDeletionEvent, and WMI will use its own event subsystem to deliver events. Here is a sample WQL query that subscribes to Win32_Process creation events:
"Select * From __InstanceCreationEvent Within 5 Where TargetInstance Isa 'Win32_Process'"
In this case you have to use the Within clause