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EventInstance Constructor (Int64, Int32)

Initializes a new instance of the EventInstance class using the specified resource identifiers for the localized message and category text of the event entry.

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

public EventInstance(
	long instanceId,
	int categoryId
)

Parameters

instanceId
Type: System.Int64
A resource identifier that corresponds to a string defined in the message resource file of the event source.
categoryId
Type: System.Int32
A resource identifier that corresponds to a string defined in the category resource file of the event source, or zero to specify no category for the event.

ExceptionCondition
ArgumentOutOfRangeException

The instanceId parameter is a negative value or a value larger than UInt32.MaxValue.

-or-

The categoryId parameter is a negative value or a value larger than UInt16.MaxValue.

To write an informational entry to an event log, initialize an EventInstance and pass it to the WriteEvent method. Set the instanceId to the resource identifier of the event message in the corresponding MessageResourceFile property for the source. Set the categoryId to a numeric category value, or the resource identifier of the event category in the CategoryResourceFile property for the source; set the categoryId to zero for no event category. The EntryType property for the new instance is set to Information by default.

The Event Viewer uses the resource identifiers to display the corresponding strings from the localized resource files for the source. You must register the source with the corresponding resource files before you can write events using resource identifiers.

The following code example writes an informational event entry, and then reuses the EventInstance to write an entry for a warning event to an existing event log. The event message text is specified using a resource identifier in a message resource file. The code example assumes that the corresponding message resource file has been registered for the source.



            // Ensure that the source has already been registered using
            // EventLogInstaller or EventLog.CreateEventSource.

            string sourceName = "SampleApplicationSource";
            if(EventLog.SourceExists(sourceName))
            {
                // Define an informational event with no category.
                // The message identifier corresponds to the message text in the
                // message resource file defined for the source.
                EventInstance myEvent = new EventInstance(UpdateCycleCompleteMsgId, 0);

                // Write the event to the event log using the registered source.
                EventLog.WriteEvent(sourceName, myEvent);

                // Reuse the event data instance for another event entry.
                // Set the entry category and message identifiers for
                // the appropriate resource identifiers in the resource files
                // for the registered source.  Set the event type to Warning.

                myEvent.CategoryId = RefreshCategoryMsgId;
                myEvent.EntryType = EventLogEntryType.Warning;
                myEvent.InstanceId = ServerConnectionDownMsgId;

                // Write the event to the event log using the registered source.
                // Insert the machine name into the event message text.
                EventLog.WriteEvent(sourceName, myEvent, Environment.MachineName);
            }
            else 
            {
                Console.WriteLine("Warning - event source {0} not registered", 
                    sourceName);
            }



The code example uses the following message text file, built into the resource library EventLogMsgs.dll. A message text file is the source from which the message resource file is created. The message text file defines the resource identifiers and text for the category, event message, and parameter insertion strings.

; // EventLogMsgs.mc
; // ********************************************************

; // Use the following commands to build this file:

; //   mc -s EventLogMsgs.mc
; //   rc EventLogMsgs.rc
; //   link /DLL /SUBSYSTEM:WINDOWS /NOENTRY /MACHINE:x86 EventLogMsgs.Res 
; // ********************************************************

; // - Event categories -
; // Categories must be numbered consecutively starting at 1.
; // ********************************************************

MessageId=0x1
Severity=Success
SymbolicName=INSTALL_CATEGORY
Language=English
Installation
.

MessageId=0x2
Severity=Success
SymbolicName=QUERY_CATEGORY
Language=English
Database Query
.

MessageId=0x3
Severity=Success
SymbolicName=REFRESH_CATEGORY
Language=English
Data Refresh
.

; // - Event messages -
; // *********************************

MessageId = 1000
Severity = Success
Facility = Application
SymbolicName = AUDIT_SUCCESS_MESSAGE_ID_1000
Language=English
My application message text, in English, for message id 1000, called from %1.
.

MessageId = 1001
Severity = Warning
Facility = Application
SymbolicName = AUDIT_FAILED_MESSAGE_ID_1001
Language=English
My application message text, in English, for message id 1001, called from %1.
.


MessageId = 1002
Severity = Success
Facility = Application
SymbolicName = GENERIC_INFO_MESSAGE_ID_1002
Language=English
My generic information message in English, for message id 1002.
.


MessageId = 1003
Severity = Warning
Facility = Application
SymbolicName = GENERIC_WARNING_MESSAGE_ID_1003
Language=English
My generic warning message in English, for message id 1003, called from %1.
.


MessageId = 1004
Severity = Success
Facility = Application
SymbolicName = UPDATE_CYCLE_COMPLETE_MESSAGE_ID_1004
Language=English
The update cycle is complete for %%5002.
.


MessageId = 1005
Severity = Warning
Facility = Application
SymbolicName = SERVER_CONNECTION_DOWN_MESSAGE_ID_1005
Language=English
The refresh operation did not complete because the connection to server %1 could not be established.
.


; // - Event log display name -
; // ********************************************************


MessageId = 5001
Severity = Success
Facility = Application
SymbolicName = EVENT_LOG_DISPLAY_NAME_MSGID
Language=English
Sample Event Log
.



; // - Event message parameters -
; //   Language independent insertion strings
; // ********************************************************


MessageId = 5002
Severity = Success
Facility = Application
SymbolicName = EVENT_LOG_SERVICE_NAME_MSGID
Language=English
SVC_UPDATE.EXE
.

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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