This base class is the basis for all variable length events. Derive from this class to create your own custom events.

For a list of all members of this type, see CVariableLengthBaseEvent Members.

CVariableLengthBaseEvent

[C++]
class CVariableLengthBaseEvent

Example

[C++]
class CEventVariableLen: 
    public CVariableLengthBaseEvent<EVENT_VARIABLE_LEN, &MY_VARIABLE_LEN_EVENTCLASS>
{
public:
    CEventVariableLen(LPCWSTR lpszString1, LPCWSTR lpszString2, 
        LPCWSTR lpszString3) 
    { 
        // Firstly, you must calculate the size of event structure
        int nSize = sizeof(_EventDataType) + 
            StringSizeInBytes(lpszString1) + 
            StringSizeInBytes(lpszString2) + 
            StringSizeInBytes(lpszString3);

        // Initialize the event. This creates the structure in m_pData and 
        // sets up standard event details, like the event type, the event 
        // guid, etc...
        InitEventData(nSize, EVENT_TRACE_TYPE_INFO);
        //
        // Set your event data
        //
        m_pData->Data.dwProcessID = GetCurrentProcessId();
        m_pData->Data.dwThreadID = GetCurrentThreadId();

        // Notice how the string offsets are calculated. 
        CopyString(m_pData->Data.szStringData, lpszString1);

        CopyString(LPWSTR(int(m_pData->Data.szStringData) + 
            StringSizeInBytes(lpszString1)), lpszString2);
		
        CopyString(LPWSTR(int(m_pData->Data.szStringData) + 
            StringSizeInBytes(lpszString1) +
            StringSizeInBytes(lpszString2)), lpszString3);

        // Again, if you need to, you can set specific values in the event 
        // header through m_pData->Header.

        //
        // Set text equivelent of the event for verbose debug output. You
        // don't have to do this, but it might be handy to do so?
        //
        SetTextEvent("Process ID = 0x%X, Thread ID = 0x%X, String1 = '%ls',"\
            "String2 = '%ls', String3 = '%ls'\n", m_pData->Data.dwProcessID, 
            m_pData->Data.dwThreadID, lpszString1, lpszString2, lpszString3);
    }
};

Requirements

Platforms:  Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

Header: Declared in WMIEventTracing.h

 

See Also

CVariableLengthBaseEvent Members | CTraceEvent Members | CTraceController Members | CBaseEvent Members