EventSource.WriteEventWithRelatedActivityIdCore(Int32, Guid*, Int32, EventSource+EventData*) EventSource.WriteEventWithRelatedActivityIdCore(Int32, Guid*, Int32, EventSource+EventData*) EventSource.WriteEventWithRelatedActivityIdCore(Int32, Guid*, Int32, EventSource+EventData*) Method



This API is not CLS-compliant.

Writes an event that indicates that the current activity is related to another activity.

 void WriteEventWithRelatedActivityIdCore(int eventId, Guid* childActivityID, int eventDataCount, System::Diagnostics::Tracing::EventSource::EventData* data);
protected void WriteEventWithRelatedActivityIdCore (int eventId, Guid* childActivityID, int eventDataCount, System.Diagnostics.Tracing.EventSource.EventData* data);
member this.WriteEventWithRelatedActivityIdCore : int * nativeptr<Guid> * int * nativeptr<System.Diagnostics.Tracing.EventSource.EventData> -> unit


Int32 Int32 Int32

An identifier that uniquely identifies this event within the EventSource.


A pointer to the GUID of the related activity ID.

Int32 Int32 Int32

The number of items in the data field.


A pointer to the first item in the event data field.


The following C# code example shows how to define a method overload that calls WriteEventWithRelatedActivityIdCore.

[EventSource(Name = "Litware-ProductName-ComponentName")]
public sealed class LitwareComponentNameEventSource : EventSource
    [Event(1, Task = Tasks.Request, Opcode = EventOpcode.Send)]
    public void RequestStart(Guid relatedActivityId, int reqId, string url)
        WriteEventWithRelatedActivityIdCore(1, relatedActivityId, reqId, url);


<EventSource(Name:="Litware-ProductName-ComponentName")> _
Public NotInheritable Class LitwareComponentNameEventSource
    Inherits EventSource
    <[Event](1, Task:=Tasks.Request, Opcode:=EventOpcode.Send)> _
    Public Sub RequestStart(relatedActivityId As Guid, reqId As Integer, url As String)
        WriteEventWithRelatedActivityIdCore(1, relatedActivityId, reqId, url)
    End Sub

End Class

#region Keywords / Task / Opcodes
public static class Tasks
    public const EventTask Request = (EventTask)0x1;
#Region "Keywords / Task / Opcodes"
    Public NotInheritable Class Tasks
        Private Sub New()
        End Sub
        Public Const Request As EventTask = DirectCast(&H1, EventTask)
    End Class
#End Region


WriteEventWithRelatedActivityIdCore is similar to the WriteEventWithRelatedActivityId method but offers better performance, bevcause it does not have to unbox the childActivityID and data arguments.

Your ETW event method calling this function must follow these guidelines:

  1. Specify the first parameter as a Guid named relatedActivityId.

  2. Specify either Send or Receive as the EventAttribute.Opcode property.

  3. Call WriteEventWithRelatedActivityIdCore passing in the event ID, followed by the related ID GUID, followed by all the parameters the event method is passed, in the same order.

Applies to