TraceSource::TraceEvent Method (TraceEventType, Int32, String^, array<Object^>^)


The .NET API Reference documentation has a new home. Visit the .NET API Browser on to see the new experience.

Writes a trace event to the trace listeners in the Listeners collection using the specified event type, event identifier, and argument array and format.

Namespace:   System.Diagnostics
Assembly:  System (in System.dll)

void TraceEvent(
	TraceEventType eventType,
	int id,
	String^ format,
	... array<Object^>^ args


Type: System.Diagnostics::TraceEventType

One of the enumeration values that specifies the event type of the trace data.

Type: System::Int32

A numeric identifier for the event.

Type: System::String^

A composite format string (see Remarks) that contains text intermixed with zero or more format items, which correspond to objects in the args array.

Type: array<System::Object^>^

An object array containing zero or more objects to format.

Exception Condition

format is null.


format is invalid.


The number that indicates an argument to format is less than zero, or greater than or equal to the number of specified objects to format.


An attempt was made to trace an event during finalization.

For more information about the format parameter, see Composite Formatting.

The TraceEvent method is intended to trace events that can be processed automatically by tools. For example, a monitoring tool can notify an administrator if a specific event is traced by a specific source.

The TraceEvent method calls the ShouldTrace method of the SourceSwitch object returned by the Switch property. If ShouldTrace returns true, TraceEvent calls the corresponding TraceEvent method of each listener. Otherwise, TraceEvent returns without calling the listeners' methods.

The trace content is listener specific. The default TraceEvent(TraceEventCache^, String^, TraceEventType, Int32, String^, array<Object^>^) method writes the source name, event type, and numeric identity in the trace header, then calls the String::Format(IFormatProvider^, String^, array<Object^>^) method, passing the format string and args array and using the CultureInfo::InvariantCulture property to format the string as the message output.


The EventLogTraceListener object is limited to a maximum id value of 65,535. If the id value specified is greater than 65,535, the EventLogTraceListener object uses 65,535.

The following code example shows the use of the TraceEvent(TraceEventType, Int32) method to pass a trace event to the listeners. This code example is part of a larger example provided for the TraceSource class.

No code example is currently available or this language may not be supported.

.NET Framework
Available since 2.0
Return to top