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EventLogWatcher Class

Allows you to subscribe to incoming events. Each time a desired event is published to an event log, the EventRecordWritten event is raised, and the method that handles this event will be executed.


Namespace:  System.Diagnostics.Eventing.Reader
Assembly:  System.Core (in System.Core.dll)

[HostProtectionAttribute(SecurityAction.LinkDemand, MayLeakOnAbort = true)]
public class EventLogWatcher : IDisposable

The EventLogWatcher type exposes the following members.

Public methodEventLogWatcher(EventLogQuery)Initializes a new instance of the EventLogWatcher class by specifying an event query.
Public methodEventLogWatcher(String)Initializes a new instance of the EventLogWatcher class by specifying the name or path to an event log.
Public methodEventLogWatcher(EventLogQuery, EventBookmark)Initializes a new instance of the EventLogWatcher class by specifying an event query and a bookmark that is used as starting position for the query.
Public methodEventLogWatcher(EventLogQuery, EventBookmark, Boolean)Initializes a new instance of the EventLogWatcher class by specifying an event query, a bookmark that is used as starting position for the query, and a Boolean value that determines whether to read the events that already exist in the event log.

Public propertyEnabledDetermines whether this object starts delivering events to the event delegate.

Public methodDispose()Releases all the resources used by this object.
Protected methodDispose(Boolean)Releases the unmanaged resources used by this object, and optionally releases the managed resources.
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeServes as the default hash function. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)

Public eventEventRecordWrittenAllows setting a delegate (event handler method) that gets called every time an event is published that matches the criteria specified in the event query for this object.

The instances of this class are created from EventLogQuery objects, which specify a query for the event subscription. When an event is logged that matches the criteria expressed in the query, then the EventRecordWritten event is raised.


The HostProtectionAttribute attribute applied to this type or member has the following Resources property value: MayLeakOnAbort. The HostProtectionAttribute does not affect desktop applications (which are typically started by double-clicking an icon, typing a command, or entering a URL in a browser). For more information, see the HostProtectionAttribute class or SQL Server Programming and Host Protection Attributes.

For example code using this class, see How to: Subscribe to Events in an Event Log.

.NET Framework

Supported in: 4.5, 4, 3.5

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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