Message Files

Each event source should register message files that contain description strings for each event identifier, event category, and parameter. Register these files in the EventMessageFile, CategoryMessageFile, and ParameterMessageFile registry values for the event source.

You can create one message file that contains descriptions for the event identifiers, categories, and parameters, or create three separate message files. The message identifiers for all of your messages should be unique whether you specify the messages in one file or three files. Several applications can share the same message file. For more information on message files, see Message Compiler. For details on the syntax of a message file, see Message Text Files.

Example Message File

The following is an example message file.

; /* --------------------------------------------------------
; HEADER SECTION
;*/
SeverityNames=(Success=0x0:STATUS_SEVERITY_SUCCESS
               Informational=0x1:STATUS_SEVERITY_INFORMATIONAL
               Warning=0x2:STATUS_SEVERITY_WARNING
               Error=0x3:STATUS_SEVERITY_ERROR
              )
;
;
FacilityNames=(System=0x0:FACILITY_SYSTEM
               Runtime=0x2:FACILITY_RUNTIME
               Stubs=0x3:FACILITY_STUBS
               Io=0x4:FACILITY_IO_ERROR_CODE
              )
;
;/* ------------------------------------------------------------------
; MESSAGE DEFINITION SECTION
;*/

MessageIdTypedef=WORD

MessageId=0x1
SymbolicName=CAT_1
Language=English
Category 1
.

MessageId=0x2
SymbolicName=CAT_2
Language=English
Category 2
.

MessageId=0x3
SymbolicName=CAT_3
Language=English
Category 3
.

MessageIdTypedef=DWORD

MessageId=0x100
Severity=Error
Facility=Runtime
SymbolicName=MSG_COMMAND_ERR
Language=English
The command is incorrect. 
.

MessageId=0x101
Severity=Success
Facility=System
SymbolicName=MSG_STRIKE_ANY_KEY
Language=English
Press any key to continue . . . %0
.

MessageId=0x102
Severity=Error
Facility=System
SymbolicName=MSG_FILE_BAD_CONTENTS
Language=English
File %1 contains %2, which is in error
.

MessageId=0x103
Severity=Warning
Facility=System
SymbolicName=MSG_RETRYS
Language=English
There have been %1 retrys with %2 success! Disconnect from
the server and retry later.
.

MessageId=0x104
Severity=Informational
Facility=System
SymbolicName=MSG_INSERT_DISK
Language=English
Insert %%1000 in %%1001 and hit any key when ready... 
.

;/* Insert string parameters */
;

MessageId=1000
Severity=Success
Facility=System
SymbolicName=DISK
Language=English
disk%0
.

MessageId=1001
Severity=Success
Facility=System
SymbolicName=DRIVE
Language=English
drive%0
.

The event-viewing application can use the following procedure to gain access to the message strings in the message DLL.

To obtain description strings

1. Call the RegOpenKey function to open the event source.
2. Call the RegQueryValueEx function to obtain the contents of the EventMessageFile value for the event source, which is the name of the message DLL.
3. Call the LoadLibraryEx function to load the message DLL determined by step 2.
4. Call the FormatMessage function with the message identifier to obtain the description from the DLL. (Note that the messages identifiers are defined in the .H file generated by the message compiler.) The FormatMessage function will replace the insertion strings using the argument values that you pass but it will not replace the parameter insertion strings; you must replace the parameter insertion strings yourself before displaying the string.