Segnalazione di eventi

Per segnalare gli eventi, è prima necessario definire gli eventi in un file di testo del messaggio. Per informazioni dettagliate sulla scrittura di un file di testo del messaggio, vedere File di testo dei messaggi. Di seguito viene illustrato il file di testo del messaggio usato in questo esempio.

; // MyEventProvider.mc 

; // This is the 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
              )

LanguageNames=(English=0x409:MSG00409)


; // The following are the categories of events.

MessageIdTypedef=WORD

MessageId=0x1
SymbolicName=NETWORK_CATEGORY
Language=English
Network Events
.

MessageId=0x2
SymbolicName=DATABASE_CATEGORY
Language=English
Database Events
.

MessageId=0x3
SymbolicName=UI_CATEGORY
Language=English
UI Events
.


; // The following are the message definitions.

MessageIdTypedef=DWORD

MessageId=0x100
Severity=Error
Facility=Runtime
SymbolicName=MSG_INVALID_COMMAND
Language=English
The command is not valid.
.


MessageId=0x101
Severity=Error
Facility=System
SymbolicName=MSG_BAD_FILE_CONTENTS
Language=English
File %1 contains content that is not valid.
.

MessageId=0x102
Severity=Warning
Facility=System
SymbolicName=MSG_RETRIES
Language=English
There have been %1 retries with %2 success! Disconnect from
the server and try again later.
.

MessageId=0x103
Severity=Informational
Facility=System
SymbolicName=MSG_COMPUTE_CONVERSION
Language=English
%1 %%4096 = %2 %%4097. 
.


; // The following are the parameter strings */


MessageId=0x1000
Severity=Success
Facility=System
SymbolicName=QUARTS_UNITS
Language=English
quarts%0
.

MessageId=0x1001
Severity=Success
Facility=System
SymbolicName=GALLONS_UNITS
Language=English
gallons%0
.

Per compilare il file di testo del messaggio, usare il comando seguente:

mc -U provider.mc

Per compilare le risorse generate dal compilatore di messaggi, usare il comando seguente:

rc provider.rc

Per creare la DLL solo risorsa contenente le risorse della stringa della tabella dei messaggi, usare il comando seguente (è possibile eseguire il comando da un prompt dei comandi Visual Studio):

link -dll -noentry provider.res

Di seguito viene illustrato il file di intestazione generato dal compilatore per il file di testo del messaggio precedente. Includere il file di intestazione nel progetto.

// MyEventProvider.mc 
// This is the header section.
// The following are categories of events.
//
//  Values are 32 bit values laid out as follows:
//
//   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
//   1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
//  +---+-+-+-----------------------+-------------------------------+
//  |Sev|C|R|     Facility          |               Code            |
//  +---+-+-+-----------------------+-------------------------------+
//
//  where
//
//      Sev - is the severity code
//
//          00 - Success
//          01 - Informational
//          10 - Warning
//          11 - Error
//
//      C - is the Customer code flag
//
//      R - is a reserved bit
//
//      Facility - is the facility code
//
//      Code - is the facility's status code
//
//
// Define the facility codes
//
#define FACILITY_SYSTEM                  0x0
#define FACILITY_STUBS                   0x3
#define FACILITY_RUNTIME                 0x2
#define FACILITY_IO_ERROR_CODE           0x4


//
// Define the severity codes
//
#define STATUS_SEVERITY_WARNING          0x2
#define STATUS_SEVERITY_SUCCESS          0x0
#define STATUS_SEVERITY_INFORMATIONAL    0x1
#define STATUS_SEVERITY_ERROR            0x3


//
// MessageId: NETWORK_CATEGORY
//
// MessageText:
//
// Network Events
//
#define NETWORK_CATEGORY                 ((WORD)0x00000001L)

//
// MessageId: DATABASE_CATEGORY
//
// MessageText:
//
// Database Events
//
#define DATABASE_CATEGORY                ((WORD)0x00000002L)

//
// MessageId: UI_CATEGORY
//
// MessageText:
//
// UI Events
//
#define UI_CATEGORY                      ((WORD)0x00000003L)

 // The following are message definitions.
//
// MessageId: MSG_INVALID_COMMAND
//
// MessageText:
//
// The command is not valid.
//
#define MSG_INVALID_COMMAND              ((DWORD)0xC0020100L)

//
// MessageId: MSG_BAD_FILE_CONTENTS
//
// MessageText:
//
// File %1 contains content that is not valid.
//
#define MSG_BAD_FILE_CONTENTS            ((DWORD)0xC0000101L)

//
// MessageId: MSG_RETRIES
//
// MessageText:
//
// There have been %1 retries with %2 success! Disconnect from
// the server and try again later.
//
#define MSG_RETRIES                      ((DWORD)0x80000102L)

//
// MessageId: MSG_COMPUTE_CONVERSION
//
// MessageText:
//
// %1 %%4096 = %2 %%4097. 
//
#define MSG_COMPUTE_CONVERSION           ((DWORD)0x40000103L)

 // The following are the parameter strings */
//
// MessageId: QUARTS_UNITS
//
// MessageText:
//
// quarts%0
//
#define QUARTS_UNITS                     ((DWORD)0x00001000L)

//
// MessageId: GALLONS_UNITS
//
// MessageText:
//
// gallons%0
//
#define GALLONS_UNITS                    ((DWORD)0x00001001L)

Nell'esempio seguente viene illustrato come usare la funzione ReportEvent per scrivere gli eventi definiti nel file di testo del messaggio precedente.

#ifndef UNICODE
#define UNICODE
#endif
#include <windows.h>
#include <stdio.h>
#include "provider.h"

#pragma comment(lib, "advapi32.lib")

#define PROVIDER_NAME L"MyEventProvider"

// Hardcoded insert string for the event messages.
CONST LPCWSTR pBadCommand = L"The command that was not valid";
CONST LPCWSTR pFilename = L"c:\\folder\\file.ext";
CONST LPCWSTR pNumberOfRetries = L"3";
CONST LPCWSTR pSuccessfulRetries = L"0";
CONST LPCWSTR pQuarts = L"8";
CONST LPCWSTR pGallons = L"2";

void wmain(void)
{
    HANDLE hEventLog = NULL;
    LPCWSTR pInsertStrings[2] = { NULL, NULL };
    DWORD dwEventDataSize = 0;

    // The source name (provider) must exist as a subkey of Application.
    hEventLog = RegisterEventSource(NULL, PROVIDER_NAME);
    if (NULL == hEventLog)
    {
        wprintf(L"RegisterEventSource failed with 0x%x.\n", GetLastError());
        goto cleanup;
    }

    // This event includes user-defined data as part of the event. The event message
    // does not use insert strings.
    dwEventDataSize = ((DWORD)wcslen(pBadCommand) + 1) * sizeof(WCHAR);
    if (!ReportEvent(hEventLog, EVENTLOG_ERROR_TYPE, UI_CATEGORY, MSG_INVALID_COMMAND, NULL, 0, dwEventDataSize, NULL, const_cast<LPWSTR>(pBadCommand)))
    {
        wprintf(L"ReportEvent failed with 0x%x for event 0x%x.\n", GetLastError(), MSG_INVALID_COMMAND);
        goto cleanup;
    }

    // This event uses insert strings.
    pInsertStrings[0] = pFilename;
    if (!ReportEvent(hEventLog, EVENTLOG_ERROR_TYPE, DATABASE_CATEGORY, MSG_BAD_FILE_CONTENTS, NULL, 1, 0, (LPCWSTR*)pInsertStrings, NULL))
    {
        wprintf(L"ReportEvent failed with 0x%x for event 0x%x.\n", GetLastError(), MSG_BAD_FILE_CONTENTS);
        goto cleanup;
    }

    // This event uses insert strings.
    pInsertStrings[0] = pNumberOfRetries;
    pInsertStrings[1] = pSuccessfulRetries;
    if (!ReportEvent(hEventLog, EVENTLOG_WARNING_TYPE, NETWORK_CATEGORY, MSG_RETRIES, NULL, 2, 0, (LPCWSTR*)pInsertStrings, NULL))
    {
        wprintf(L"ReportEvent failed with 0x%x for event 0x%x.\n", GetLastError(), MSG_RETRIES);
        goto cleanup;
    }

    // This event uses insert strings.
    pInsertStrings[0] = pQuarts;
    pInsertStrings[1] = pGallons;
    if (!ReportEvent(hEventLog, EVENTLOG_INFORMATION_TYPE, UI_CATEGORY, MSG_COMPUTE_CONVERSION, NULL, 2, 0, (LPCWSTR*)pInsertStrings, NULL))
    {
        wprintf(L"ReportEvent failed with 0x%x for event 0x%x.\n", GetLastError(), MSG_COMPUTE_CONVERSION);
        goto cleanup;
    }

    wprintf(L"All events successfully reported.\n");

cleanup:

    if (hEventLog)
        DeregisterEventSource(hEventLog);
}

Prima di eseguire questo esempio, registrare il provider nel Registro di sistema. Per informazioni dettagliate sulle impostazioni del Registro di sistema, vedere Origini eventi. Aggiungere "MyEventProvider" come chiave del Registro di sistema nella chiave seguente:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\eventlog\Application

Di seguito vengono illustrati i valori del Registro di sistema da impostare per la chiave del Registro di sistema "MyEventProvider".