如何以编程方式在DFS中获取活动的UNC路径

Question

给定DFS路径,我如何知道它当前以编程方式存在的活动路径.

例如,我有2个服务器共享"\\Server1\Folder\","\\Server2\Folder\"并且它已打开DFS,因此可以访问它"\\DFS_Server\Folder\",我怎么知道当前所处的活动路径"\\DFS_Server\Folder\"是什么,无论是"\\Server1\Folder\"或"\\Server2\Folder\".

Answer 1

如果我正确理解您的要求,那么还有一个似乎可以满足您需求的API:

// mscorlib (no additional assemblies needed)
using System.Runtime.InteropServices;

public static class Dfs
{
    private enum NetDfsInfoLevel
    {
        DfsInfo1 = 1,
        DfsInfo2 = 2,
        DfsInfo3 = 3,
        DfsInfo4 = 4,
        DfsInfo5 = 5,
        DfsInfo6 = 6,
        DfsInfo7 = 7,
        DfsInfo8 = 8,
        DfsInfo9 = 9,
        DfsInfo50 = 50,
        DfsInfo100 = 100,
        DfsInfo150 = 150,
    }

    [DllImport("netapi32.dll", SetLastError = true)]
    private static extern int NetApiBufferFree(IntPtr buffer);

    [DllImport("Netapi32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
    private static extern int NetDfsGetInfo(
        [MarshalAs(UnmanagedType.LPWStr)] string DfsEntryPath, // DFS entry path for the volume
        [MarshalAs(UnmanagedType.LPWStr)] string ServerName,   // This parameter is currently ignored and should be NULL
        [MarshalAs(UnmanagedType.LPWStr)] string ShareName,    // This parameter is currently ignored and should be NULL.
        NetDfsInfoLevel Level,                                 // Level of information requested
        out IntPtr Buffer                                      // API allocates and returns buffer with requested info
        );

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    private struct DFS_INFO_3
    {
        [MarshalAs(UnmanagedType.LPWStr)]
        public string EntryPath;
        [MarshalAs(UnmanagedType.LPWStr)]
        public string Comment;
        public int State;
        public int NumberOfStorages;
        public IntPtr Storage;
    }

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    private struct DFS_STORAGE_INFO
    {
        public int State;
        [MarshalAs(UnmanagedType.LPWStr)]
        public string ServerName;
        [MarshalAs(UnmanagedType.LPWStr)]
        public string ShareName;
    }

    private static T GetStruct<T>(IntPtr buffer, int offset=0)where T:struct
    {
        T r = new T();
        r = (T) Marshal.PtrToStructure(buffer + offset * Marshal.SizeOf(r), typeof(T));
        return r;
    }

    public static string GetDfsInfo(string server)
    {
        string rval = null;
        IntPtr b;
        int r = NetDfsGetInfo(server, null, null, NetDfsInfoLevel.DfsInfo3, out b);
        if(r != 0)
        {
            NetApiBufferFree(b);

            // return passed string if not DFS
            return rval;
        }

        DFS_INFO_3 sRes = GetStruct<DFS_INFO_3>(b);
        if(sRes.NumberOfStorages > 0)
        {
            DFS_STORAGE_INFO sResInfo = GetStruct<DFS_STORAGE_INFO>(sRes.Storage);
            rval = string.Concat(@"\\", sResInfo.ServerName, @"\", sResInfo.ShareName, @"\");
        }

        NetApiBufferFree(b);

        return rval;
    }
}

像这样使用它:

string dfsPath = @"\\DFS_Server\Folder\";
string share = Dfs.GetDfsInfo(dfsPath)

有关API参考,请检查NetDfsGetInfo,DFS_INFO_3,DFS_STORAGE_INFO和NetApiBufferFree上的msdn.

Answer 2

尝试一下，其中 sDFSPath 是您要查询的路径，sHostServer 是您要查询 WMI 的服务器，这可以是您上面提到的两个服务器中的任何一个。您甚至可以在第一台服务器上失败时编写更优雅的代码，然后在下一台服务器上查询 WMI

public static ArrayList GetActiveServers(string sDFSPath, string sHostServer)
{
    ArrayList sHostNames = new ArrayList(); 

    ManagementPath oManagementPath = new ManagementPath();
    oManagementPath.Server = sHostServer;
    oManagementPath.NamespacePath = @"root\cimv2";

    oManagementScope = new ManagementScope(oManagementPath);
    oManagementScope.Connect();

    SelectQuery oSelectQuery = new SelectQuery();
    oSelectQuery.QueryString = @"SELECT * FROM Win32_DfsTarget WHERE LinkName LIKE '%" + sDFSPath.Replace("\\", "\\\\") + "%' and State = 1";

    ManagementObjectSearcher oObjectSearcher = new ManagementObjectSearcher(oManagementScope, oSelectQuery);
    ManagementObjectCollection oObjectCollection = oObjectSearcher.Get();

    if (oObjectCollection.Count != 0)
    {
        foreach (ManagementObject oItem in oObjectCollection)
        {
            sHostNames.Add(oItem.Properties["ServerName"].Value.ToString());
        }
    }

    return sHostNames;
}

希望这是有道理的