Registrering för omstart av program

Om du vill registrera programmet som ska startas om anropar du funktionen RegisterApplicationRestart. Windows Felrapportering (WER) startar om programmet om det har körts i minst 60 sekunder innan det slutar svara eller stöter på ett ohanterat undantag.

Du bör också överväga återställningsregistrering , vilket gör att du kan spara data och statusinformation som kan vara till hjälp när WER startar om din applikation. WER startar om programmet när återställningsprocessen har slutförts, om du även registrerar dig för återställning.

När återställningsprocessen är klar avslutar WER programmet och startar sedan om det. För konsolprogram startas programmet i ett separat konsolfönster som stängs när programmet avslutas.

Anmärkning för programinstallationsförfattare: Registrering för omstart av program gör också att Windows startar om programmet automatiskt när datorn startas om i fall där datorn startas om på grund av en programuppdatering. För att det ska fungera måste programmets installationsprogram anropa funktionen ExitWindowsEx med EWX_RESTARTAPPS-flagguppsättningen eller funktionen InitiateShutdown med SHUTDOWN_RESTARTAPPS-flagguppsättningen.

I följande exempel visas hur du registrerar dig så att WER startar om programmet. Exemplet orsakar en åtkomstöverträdelse när du har registrerat dig för omstart av programmet. Åtkomstöverträdelsen hämtas av Windows Felrapportering och visar användarupplevelsen för felrapportering, inklusive omstart av program. Den ska köras från ett konsolfönster utan kommandoradsargument.

#include <windows.h>
#include <stdio.h>
#include <strsafe.h>

#define RESTART_SWITCH L"/restart"

void GetRestartInfo(int argc, wchar_t* argv[], BOOL* pfIsRestart, DWORD* pdwRecordId); 
DWORD InitApplication(BOOL fIsRestart, DWORD* pdwRecordId); 
BOOL WINAPI CtrlHandler(DWORD dwControlType);
DWORD WINAPI Recover(PVOID pContext);

// A simple example to show how to use application recovery. For simplicity,
// the state information (record ID) is passed as part of the command line. 
void wmain(int argc, wchar_t* argv[])
{
    HRESULT hr = S_OK;
    DWORD dwRecordId = 0;
    BOOL fIsRestart = FALSE;

    GetRestartInfo(argc, argv, &fIsRestart, &dwRecordId);

    if (FAILED(hr = InitApplication(fIsRestart, &dwRecordId)))
    {
        wprintf(L"Failed to initialize the application.\n");
        goto cleanup;
    }

    // Do work. If you have a lot of state information, you should
    // periodically persist the state information to save time
    // in the recovery process.

    // The application must exist for at least 60 seconds for the
    // application to be restarted. Use Sleep() to mimic 60 seconds
    // worth of work.
    wprintf(L"Sleeping...\n");
    Sleep(62 * 1000);

    // Set the record ID to verify restart value.
    dwRecordId = 10;

    // Generate an access violation to force a restart. If we've already
    // restarted just exit because the example already demonstrated
    // the restart feature.
    if (FALSE == fIsRestart)
    {
        wprintf(L"Causing access violation...\n");
        int* p = NULL;
        *p = 5;
    }

cleanup:

    wprintf(L"Exiting...\n");
}


// Get the restart info from the command line. The command line is 
// of the form, /restart -r <RecordId>. The application 
// is being restarted if the first argument is /restart.
void GetRestartInfo(int argc, wchar_t* argv[], BOOL* pfIsRestart, DWORD* pdwRecordId) 
{
    if (argc > 1)
    {
        if (!wcsncmp(RESTART_SWITCH, argv[1], sizeof(RESTART_SWITCH)))
        {
            *pfIsRestart = TRUE;
            *pdwRecordId = _wtoi(argv[3]);
        }
    }

}

// Initialize the application. If this is a restart, use the state 
// information to reset the state of the application. This example 
// does not fail the initialization process if the process of 
// registering for application recovery and restart failed.
DWORD InitApplication(BOOL fIsRestart, DWORD* pdwRecordId)
{
    DWORD status = ERROR_SUCCESS;  // Set only if the initializing the application fails,
    HRESULT hr = S_OK;             // not if registering for recovery and restart fails.
    WCHAR wsCommandLine[RESTART_MAX_CMD_LINE];

    wprintf(L"Entering InitApplication...\n");

    if (fIsRestart)
    {
        // TODO: Use the record ID to initialize the application.
        wprintf(L"Restart record ID is %lu\n", *pdwRecordId);
    }
    else
    {
        // This is not a restart, so initialize the application accordingly.
    }

    // Register for restart. The command line is updated in the recovery callback.
    RtlZeroMemory(wsCommandLine, sizeof(wsCommandLine));
    StringCchPrintf(wsCommandLine, sizeof(wsCommandLine), L"/restart -r %lu", *pdwRecordId);

    hr = RegisterApplicationRestart(wsCommandLine, RESTART_NO_PATCH | RESTART_NO_REBOOT);
    if (FAILED(hr))
    {
        // Not failing because the registration failed.
        wprintf(L"RegisterApplicationRestart failed with ox%x.\n", hr);
        goto cleanup;
    }

    // Register the callback that handles the control event notifications.
    // Used for recovery when an installer is updating a component of the
    // application.
    if (!SetConsoleCtrlHandler(CtrlHandler, TRUE))
    {
        // Not failing initialization because the registration failed.
        // Consider calling UnregisterApplicationRestart if you must
        // have the latest state information.
        wprintf(L"SetConsoleCtrlHandler failed.\n");
        goto cleanup;
    }

    // Register the callback that handles recovery when the application
    // encounters an unhandled exception or becomes unresponsive.
    hr = RegisterApplicationRecoveryCallback(Recover, pdwRecordId, RECOVERY_DEFAULT_PING_INTERVAL, 0);
    if (FAILED(hr))
    {
        // Not failing initialization because the registration failed.
        // Consider calling UnregisterApplicationRestart if you must
        // have the latest state information.
        wprintf(L"RegisterApplicationRecoveryCallback failed with ox%x.\n", hr);
        goto cleanup;
    }

cleanup:

    return hr;
}


// Implement the callback for handling control character events.
// You'd implement this callback if an installer could update a
// component of your application. The system sends a CTRL_C_EVENT
// notification when an installer needs to shutdown your application
// or restart the computer in order to complete the installation.
// You can use the CTRL_C_EVENT to save final state information or
// data before exiting.
BOOL WINAPI CtrlHandler(DWORD dwControlType)
{
    wprintf(L"Entering CtrlHandler...\n");

    switch (dwControlType)
    {
        case CTRL_C_EVENT:
            wprintf(L"Handling CTRL_C_EVENT\n");
            return FALSE;

        // Other cases go here.

        default: 
            wprintf(L"Other, %ul\n", dwControlType);
            return FALSE;
    }
}


// Implement the recovery callback. This callback lets the application
// save state information or data in the event that the application
// encounters an unhandled exception or becomes unresponsive.
DWORD WINAPI Recover(PVOID pContext)
{
    HRESULT hr = S_OK;
    BOOL bCanceled = FALSE;
    DWORD dwRecordId = *(DWORD*)pContext;
    WCHAR wsCommandLine[RESTART_MAX_CMD_LINE];

    wprintf(L"Entering Recover callback...\n");

    // Do recovery work. 

    // Update the restart command line.
    RtlZeroMemory(wsCommandLine, sizeof(wsCommandLine));
    StringCchPrintf(wsCommandLine, sizeof(wsCommandLine), L"/restart -r %lu", dwRecordId);

    hr = RegisterApplicationRestart(wsCommandLine, RESTART_NO_PATCH | RESTART_NO_REBOOT);
    if (FAILED(hr))
    {
        // Not failing because the registration failed.
        wprintf(L"RegisterApplicationRestart failed with ox%x.\n", hr);
    }

    // You must call the ApplicationRecoveryInProgress function within
    // the specified ping interval or the recovery callback exits.
    // Typically, you would do a block of work, call the function, and repeat.
    hr = ApplicationRecoveryInProgress(&bCanceled);
    if (bCanceled)  
    {
        wprintf(L"Recovery was canceled by the user.\n");
        goto cleanup;
    }

    // Do more recovery work. 
    
    // You could also call the RegisterApplicationRestart function to
    // update the command line used for the restart.

cleanup:

    // Save the state file.

    wprintf(L"Leaving Recover callback...\n");
    ApplicationRecoveryFinished((bCanceled) ? FALSE: TRUE);

    return 0;
}