<PackageReference Include="System.Diagnostics.EventLog" Version="5.0.0-rc.1.20451.14" />

EventRecordWrittenEventArgs

public sealed class EventRecordWrittenEventArgs : EventArgs
When the EventRecordWritten event is raised, an instance of this object is passed to the delegate method that handles the event. This object contains the event that was published to the event log or the exception that occurred when the event subscription failed.
public Exception EventException { get; }

Gets the exception that occurred when the event subscription failed. The exception has a description of why the subscription failed.

public EventRecord EventRecord { get; }

Gets the event record that is published to the event log. This event matches the criteria from the query specified in the event subscription.