TraceLoggingLevel macro (traceloggingprovider.h)

Article
02/22/2024

TraceLogging wrapper macro that sets the level for the event.

Syntax

void TraceLoggingLevel(
  [in]  eventLevel
);

Parameters

[in] eventLevel

An 8-bit number used to describe an event's severity or importance. This value must be a compile-time constant in the range 0 to 255. If no TraceLoggingLevel arguments are provided to a TraceLoggingWrite call, the event's level will default to 5 (WINEVENT_LEVEL_VERBOSE).

Important

ProviderId, Level and Keyword are the primary means for filtering events. Other kinds of filtering are possible but have much higher overhead. Always assign a meaningful non-zero level and keyword to every event.

See EVENT_DESCRIPTOR for details about the event level.

Return value

None

Remarks

TraceLoggingLevel(eventLevel) can be used as a parameter to an invocation of a TraceLoggingWrite macro to set the event's level. Event level is a primary means for filtering events. Always assign a meaningful (non-zero) level to every event.

If no TraceLoggingLevel macros are provided to a TraceLoggingWrite call, the event's default level is 5 (WINEVENT_LEVEL_VERBOSE). If multiple TraceLoggingLevel macros are provided, the last value is used.

Level values 0 through 5 are defined by Microsoft (see evntrace.h and winmeta.h). Level values 6 through 15 are reserved for future definition by Microsoft. Level values 16 through 255 can be defined by the event provider.

Value	Semantics
LOG_ALWAYS (0)	Event bypasses level-based event filtering. Events should not use this level.
CRITICAL (1)	Critical error
ERROR (2)	Error
WARNING (3)	Warning
INFO (4)	Informational
VERBOSE (5)	Verbose

Event collection sessions can set a level filter, meaning that the session will only accept events where eventDescriptor.Level <= session.LevelFilter. Note that events with a level of 0 will bypass level-based filtering.

Examples

TraceLoggingWrite(
    g_hMyProvider,
    "MyWarningEventName",
    TraceLoggingLevel(WINEVENT_LEVEL_WARNING), // Levels defined in <winmeta.h>
    TraceLoggingKeyword(MyNetworkingKeyword), // Provider-defined keyword
    TraceLoggingHResult(errorCode, "Error"));

Requirements

Requirement	Value
Minimum supported client	Windows Vista [desktop apps \| UWP apps]
Minimum supported server	Windows Server 2008 [desktop apps \| UWP apps]
Target Platform	Windows
Header	traceloggingprovider.h

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