在C#中将UNC路径转换为本地路径

Question

有办法从UNC路径获取本地路径吗？

For例如：\server7\hello.jpg应该给我D:\attachments\hello.jpg

在应用windows文件名和完整路径长度限制后，我正在尝试保存UNC路径的附件。这里，我以UNC路径长度为参考，应用这些限制。但是本地路径长度比UNC路径长，因此我想我得到了下面的例外。

System.IO.PathTooLongException发生HResult=-2147024690 Message=The指定的路径、文件名或两者都太长。完全限定的文件名必须小于260个字符，目录名必须小于248个字符。Source=mscorlib StackTrace: at System.IO.PathHelper.GetFullPathName() at System.IO.Path.NormalizePath(字符串路径、布尔型fullCheck、Int32 maxPathLength、布尔型expandShortPaths) at System.IO.Path.NormalizePath(字符串路径、布尔型fullCheck、Int32 maxPathLength) at System.IO.FileStream.Init(String路径、FileMode模式、FileAccess access、Int32 rights、Boolean、FileShare share、Int32 )、选项、、String、布尔、Boolean，在Presensoft.JournalEmailVerification.EmailVerification.DownloadFailedAttachments(EmailMessage D:\Source\ProductionReleases\Release_8.0.7.0\Email Archiving\Presensoft.JournalEmailVerification\EmailVerification.cs:line 630 System.IO.FileStream..ctor中的System.IO.FileStream..ctor(字符串路径、FileMode模式、FileAccess访问、FileShare共享、Int32 bufferSize、FileOptions选项、字符串msgPath、布尔bFromProxy)的System.IO.FileStream..ctor(String path，FileMode模式)：

Answer 1

看一看这篇博客文章：从UNC路径获取本地路径

文章中的代码。此函数将采用UNC路径(例如\server\share或\server\c$\文件夹)并返回本地路径(例如c:\share或c：\文件夹)。

using System.Management;

public static string GetPath(string uncPath)
{
  try
  {
    // remove the "\\" from the UNC path and split the path
    uncPath = uncPath.Replace(@"\\", "");
    string[] uncParts = uncPath.Split(new char[] {'\\'}, StringSplitOptions.RemoveEmptyEntries);
    if (uncParts.Length < 2)
      return "[UNRESOLVED UNC PATH: " + uncPath + "]";
    // Get a connection to the server as found in the UNC path
    ManagementScope scope = new ManagementScope(@"\\" + uncParts[0] + @"\root\cimv2");
    // Query the server for the share name
    SelectQuery query = new SelectQuery("Select * From Win32_Share Where Name = '" + uncParts[1] + "'");
    ManagementObjectSearcher searcher = new ManagementObjectSearcher(scope, query);

    // Get the path
    string path = string.Empty;
    foreach (ManagementObject obj in searcher.Get())
    {
      path = obj["path"].ToString();
    }

    // Append any additional folders to the local path name
    if (uncParts.Length > 2)
    {
      for (int i = 2; i < uncParts.Length; i++)
        path = path.EndsWith(@"\") ? path + uncParts[i] : path + @"\" + uncParts[i];
    }

    return path;
  }
  catch (Exception ex)
  {
    return "[ERROR RESOLVING UNC PATH: " + uncPath + ": "+ex.Message+"]";
  }
}

该函数使用ManagementObjectSearcher在网络服务器上搜索共享。如果您没有对此服务器的读取访问权限，则需要使用不同的凭据登录。用下面的行替换ManagementScope行：

ConnectionOptions options = new ConnectionOptions();
options.Username = "username";
options.Password = "password";
ManagementScope scope = new ManagementScope(@"\\" + uncParts[0] + @"\root\cimv2", options);

Answer 2

这也适用于大多数情况。比系统管理简单一点。

public static string MakeDiskRootFromUncRoot(string astrPath)
{
    string strPath = astrPath;
    if (strPath.StartsWith("\\\\"))
    {
        strPath = strPath.Substring(2);
        int ind = strPath.IndexOf('$');
        if(ind>1 && strPath.Length >= 2)
        {
            string driveLetter = strPath.Substring(ind - 1,1);
            strPath = strPath.Substring(ind + 1);
            strPath = driveLetter + ":" + strPath;
        }

    }
    return strPath;
}

Answer 3

尽管出于DirQuota设置的目的，我自己也需要这样做。由于我的代码将作为服务器管理员运行，所以WMI查询示例是最简单的，只需重写它以提高可读性：

public static string ShareToLocalPath(string sharePath)
{
    try
    {
        var regex = new Regex(@"\\\\([^\\]*)\\([^\\]*)(\\.*)?");
        var match = regex.Match(sharePath);
        if (!match.Success) return "";

        var shareHost = match.Groups[1].Value;
        var shareName = match.Groups[2].Value;
        var shareDirs = match.Groups[3].Value;

        var scope = new ManagementScope(@"\\" + shareHost + @"\root\cimv2");
        var query = new SelectQuery("SELECT * FROM Win32_Share WHERE name = '" + shareName + "'");

        using (var searcher = new ManagementObjectSearcher(scope, query))
        {
            var result = searcher.Get();
            foreach (var item in result) return item["path"].ToString() + shareDirs;
        }

        return "";
    }
    catch (Exception)
    {
        return "";
    }
}

在幕后，这是读取服务器注册表项：

'HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\LanmanServer\Shares‘

如果您需要在目标服务器上转换没有管理员的路径，请查看Netapi32.dll的“NetShareEnum”函数。虽然您通常看不到它，但隐藏的共享和本地路径会向常规用户广播。代码更复杂一些，因为它需要DllImport，但是有一些示例，然后就像上面一样，您需要匹配共享名称。