c++ - 硬盘卷路径到完整文件路径

Question

我有一个 MSVC++ 应用程序，它以下列字符串格式吐出其他应用程序打开的文件句柄的硬盘卷路径:

\Device\HarddiskVolume4\Users\User\Documents\Visual Studio 2013\Projects\FileLocker\FileLocker\bin\Debug\Test.txt

我想将这些路径转换为 ​​Windows 中这些文件的完整路径。例如，我想将上面的硬盘卷路径转换为一个完整的 Windows 文件路径及其对应的盘符:

C:\Users\User\Documents\Visual Studio 2013\Projects\FileLocker\FileLocker\bin\Debug\Test.txt

我在网上看过，但没有找到任何明确的资源来以编程方式执行此操作。怎么做到的？

Answer 1

您应该寻找用于卷管理的 Windows API 函数之一:

Volume Management Functions

这是来自 MSDN 的示例:

Displaying Volume Paths

#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;
}

澄清一下:

卷名(或 GUID)类似于 \\?\Volume{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}

设备名称类似于\Device\HarddiskVolume1

盘符类似于C:

FindFirst/NextVolume 为您提供卷名称列表。

QueryDosDevice 从卷名称中为您提供设备名称。

GetVolumePathNamesForVolumeName 为您提供卷名中的驱动器号。