Anzeigen von Volumepfaden

Das folgende C++-Beispiel zeigt, wie alle Pfade für jedes Volume und Jedes Gerät angezeigt werden. Für jedes Volume im System sucht das Beispiel das Volume, ruft den Gerätenamen ab, ruft alle Pfade für dieses Volume ab und zeigt die Pfade an.

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

void DisplayVolumePaths(
        __in PWCHAR VolumeName
        )
{
    DWORD  CharCount = MAX_PATH + 1;
    PWCHAR Names     = NULL;
    PWCHAR NameIdx   = NULL;
    BOOL   Success   = FALSE;

    for (;;) 
    {
        //
        //  Allocate a buffer to hold the paths.
        Names = (PWCHAR) new BYTE [CharCount * sizeof(WCHAR)];

        if ( !Names ) 
        {
            //
            //  If memory can't be allocated, return.
            return;
        }

        //
        //  Obtain all of the paths
        //  for this volume.
        Success = GetVolumePathNamesForVolumeNameW(
            VolumeName, Names, CharCount, &CharCount
            );

        if ( Success ) 
        {
            break;
        }

        if ( GetLastError() != ERROR_MORE_DATA ) 
        {
            break;
        }

        //
        //  Try again with the
        //  new suggested size.
        delete [] Names;
        Names = NULL;
    }

    if ( Success )
    {
        //
        //  Display the various paths.
        for ( NameIdx = Names; 
              NameIdx[0] != L'\0'; 
              NameIdx += wcslen(NameIdx) + 1 ) 
        {
            wprintf(L"  %s", NameIdx);
        }
        wprintf(L"\n");
    }

    if ( Names != NULL ) 
    {
        delete [] Names;
        Names = NULL;
    }

    return;
}

void __cdecl wmain(void)
{
    DWORD  CharCount            = 0;
    WCHAR  DeviceName[MAX_PATH] = L"";
    DWORD  Error                = ERROR_SUCCESS;
    HANDLE FindHandle           = INVALID_HANDLE_VALUE;
    BOOL   Found                = FALSE;
    size_t Index                = 0;
    BOOL   Success              = FALSE;
    WCHAR  VolumeName[MAX_PATH] = L"";

    //
    //  Enumerate all volumes in the system.
    FindHandle = FindFirstVolumeW(VolumeName, ARRAYSIZE(VolumeName));

    if (FindHandle == INVALID_HANDLE_VALUE)
    {
        Error = GetLastError();
        wprintf(L"FindFirstVolumeW failed with error code %d\n", Error);
        return;
    }

    for (;;)
    {
        //
        //  Skip the \\?\ prefix and remove the trailing backslash.
        Index = wcslen(VolumeName) - 1;

        if (VolumeName[0]     != L'\\' ||
            VolumeName[1]     != L'\\' ||
            VolumeName[2]     != L'?'  ||
            VolumeName[3]     != L'\\' ||
            VolumeName[Index] != L'\\') 
        {
            Error = ERROR_BAD_PATHNAME;
            wprintf(L"FindFirstVolumeW/FindNextVolumeW returned a bad path: %s\n", VolumeName);
            break;
        }

        //
        //  QueryDosDeviceW does not allow a trailing backslash,
        //  so temporarily remove it.
        VolumeName[Index] = L'\0';

        CharCount = QueryDosDeviceW(&VolumeName[4], DeviceName, ARRAYSIZE(DeviceName)); 

        VolumeName[Index] = L'\\';

        if ( CharCount == 0 ) 
        {
            Error = GetLastError();
            wprintf(L"QueryDosDeviceW failed with error code %d\n", Error);
            break;
        }

        wprintf(L"\nFound a device:\n %s", DeviceName);
        wprintf(L"\nVolume name: %s", VolumeName);
        wprintf(L"\nPaths:");
        DisplayVolumePaths(VolumeName);

        //
        //  Move on to the next volume.
        Success = FindNextVolumeW(FindHandle, VolumeName, ARRAYSIZE(VolumeName));

        if ( !Success ) 
        {
            Error = GetLastError();

            if (Error != ERROR_NO_MORE_FILES) 
            {
                wprintf(L"FindNextVolumeW failed with error code %d\n", Error);
                break;
            }

            //
            //  Finished iterating
            //  through all the volumes.
            Error = ERROR_SUCCESS;
            break;
        }
    }

    FindVolumeClose(FindHandle);
    FindHandle = INVALID_HANDLE_VALUE;

    return;
}

Im Folgenden finden Sie eine Beispielausgabe für die Ausführung der Anwendung. Für jedes Volume enthält die Ausgabe einen Volumegerätepfad, einen Volume-GUID-Pfad und einen Laufwerkbuchstaben.

Found a device:
 \Device\HarddiskVolume2
Volume name: \\?\Volume{4c1b02c1-d990-11dc-99ae-806e6f6e6963}\
Paths:  C:\

Found a device:
 \Device\CdRom0
Volume name: \\?\Volume{4c1b02c4-d990-11dc-99ae-806e6f6e6963}\
Paths:  D:\

Zugehörige Themen

FindFirstVolume

FindNextVolume

FindVolumeClose

GetVolumePathNamesForVolumeName

QueryDosDevice