Menampilkan Jalur Volume
Contoh C++ berikut menunjukkan cara menampilkan semua jalur untuk setiap volume dan perangkat. Untuk setiap volume dalam sistem, contoh menemukan volume, mendapatkan nama perangkat, mendapatkan semua jalur untuk volume tersebut, dan menampilkan jalur.
#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;
}
Berikut ini adalah contoh output dari menjalankan aplikasi. Untuk setiap volume, output mencakup jalur perangkat volume, jalur GUID volume, dan huruf drive.
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:\
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