EventSourceCreationData(String, String) Constructor

Definition

Initializes a new instance of the EventSourceCreationData class with a specified event source and event log name.

public EventSourceCreationData (string source, string logName);

Parameters

source
String

The name to register with the event log as a source of entries.

logName
String

The name of the log to which entries from the source are written.

Examples

The following code example determines whether the event source named SampleApplicationSource is registered on the local computer. If the event source does not exist, the example sets the message resource file for the source and creates the new event source. Finally, the code example sets the localized display name for the event log, using the resource identifier value in DisplayNameMsgId and the resource file path in messageFile.

static void CreateEventSourceSample1(string messageFile)
{
    string myLogName;
    string sourceName = "SampleApplicationSource";

    // Create the event source if it does not exist.
    if(!EventLog.SourceExists(sourceName))
    {
        // Create a new event source for the custom event log
        // named "myNewLog."

        myLogName = "myNewLog";
        EventSourceCreationData mySourceData = new EventSourceCreationData(sourceName, myLogName);

        // Set the message resource file that the event source references.
        // All event resource identifiers correspond to text in this file.
        if (!System.IO.File.Exists(messageFile))
        {
            Console.WriteLine("Input message resource file does not exist - {0}",
                messageFile);
            messageFile = "";
        }
        else
        {
            // Set the specified file as the resource
            // file for message text, category text, and
            // message parameter strings.

            mySourceData.MessageResourceFile = messageFile;
            mySourceData.CategoryResourceFile = messageFile;
            mySourceData.CategoryCount = CategoryCount;
            mySourceData.ParameterResourceFile = messageFile;

            Console.WriteLine("Event source message resource file set to {0}",
                messageFile);
        }

        Console.WriteLine("Registering new source for event log.");
        EventLog.CreateEventSource(mySourceData);
    }
    else
    {
        // Get the event log corresponding to the existing source.
        myLogName = EventLog.LogNameFromSourceName(sourceName,".");
    }

    // Register the localized name of the event log.
    // For example, the actual name of the event log is "myNewLog," but
    // the event log name displayed in the Event Viewer might be
    // "Sample Application Log" or some other application-specific
    // text.
    EventLog myEventLog = new EventLog(myLogName, ".", sourceName);

    if (messageFile.Length > 0)
    {
        myEventLog.RegisterDisplayName(messageFile, DisplayNameMsgId);
    }
}

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  
.  

Remarks

To write entries to an event log, you must first create an event source for the event log. To register a new source, initialize an EventSourceCreationData instance, configure the instance properties for your application, and call the EventLog.CreateEventSource(EventSourceCreationData) method. After the source is registered, you can write entries from the source using the WriteEvent or WriteEntry methods.

You can register the event source with localized resources for your event category and message strings. Your application can write event log entries using resource identifiers, rather than specifying the actual string. The Event Viewer uses the resource identifier to find and display the corresponding string from the localized resource file based on current language settings. You can register a separate file for event categories, messages, and parameter insertion strings, or you can register the same resource file for all three types of strings. Use the CategoryCount, CategoryResourceFile, MessageResourceFile, and ParameterResourceFile properties to configure the source to write localized entries to the event log. If your application writes string values directly to the event log, you do not need to set these properties.

The source must be configured either for writing localized entries or for writing direct strings. If your application writes entries using both resource identifiers and string values, you must register two separate sources. For example, configure one source with resource files, and then use that source in the WriteEvent method to write entries using resource identifiers to the event log. Then create a different source without resource files and use that source in the WriteEntry method to write strings directly to the event log.

The following table shows initial property values for an EventSourceCreationData.

Property Initial Value
Source The source parameter.
LogName The logName parameter.
MachineName The local computer (".").
CategoryCount Zero
CategoryResourceFile null (Nothing in Visual Basic).
MessageResourceFile null (Nothing in Visual Basic).
ParameterResourceFile null (Nothing in Visual Basic).

Applies to

Product Versions
.NET 8 (package-provided), 9 (package-provided)
.NET Framework 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7 (package-provided), 4.7, 4.7.1 (package-provided), 4.7.1, 4.7.2 (package-provided), 4.7.2, 4.8 (package-provided), 4.8, 4.8.1
.NET Standard 2.0 (package-provided)
Windows Desktop 3.0, 3.1, 5, 6, 7, 8, 9

See also