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answers:

3

Hi,

I need to find out the file/directory name that a .lnk is pointing to using c#.

What is the simplest way to do this?

Thanks.

+5  A: 

This may help:

http://www.neowin.net/forum/index.php?s=3ad7f1ffb995ba84999376f574e9250f&showtopic=658928&st=0&p=589667108&#entry589667108

In essence...

Add reference to Windows Script Host Object Model in COM tab of Add Reference dialogue.

IWshRuntimeLibrary.IWshShell shell = new IWshRuntimeLibrary.WshShell();

IWshRuntimeLibrary.IWshShortcut shortcut = (IWshRuntimeLibrary.IWshShortcut)shell.CreateShortcut(link);

Console.WriteLine(shortcut.TargetPath);
Kev
I recommend against the WSH method cause it means you need another interop assembly
Sam Saffron
And that is bad why?
Kev
Wow, that was easy. One note for others, "link" in the above code is a string containing the full path name to the link (.lnk) file.
Mark T
+4  A: 

Adding to what Kev said...

If you are using csc.exe instead of Visual Studio, to add a reference to the Windows Script Host Object Model, you have to:

  • Use the tlbimp.exe tool to create a managed assembly:

    tlbimp.exe c:\windows\system32\wshom.ocx /out:IWshRuntimeLibrary.dll

  • Reference the .dll using the /r switch in csc.exe:

    csc.exe Lnk.cs /r:IWshRuntimeLibrary.dll

Bruno Gomes
+6  A: 

I wrote this for video browser, it works really well

        #region Signitures imported from http://pinvoke.net

        [DllImport("shfolder.dll", CharSet = CharSet.Auto)]
        internal static extern int SHGetFolderPath(IntPtr hwndOwner, int nFolder, IntPtr hToken, int dwFlags, StringBuilder lpszPath);

        [Flags()]
        enum SLGP_FLAGS
        {
            /// <summary>Retrieves the standard short (8.3 format) file name</summary>
            SLGP_SHORTPATH = 0x1,
            /// <summary>Retrieves the Universal Naming Convention (UNC) path name of the file</summary>
            SLGP_UNCPRIORITY = 0x2,
            /// <summary>Retrieves the raw path name. A raw path is something that might not exist and may include environment variables that need to be expanded</summary>
            SLGP_RAWPATH = 0x4
        }

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
        struct WIN32_FIND_DATAW
        {
            public uint dwFileAttributes;
            public long ftCreationTime;
            public long ftLastAccessTime;
            public long ftLastWriteTime;
            public uint nFileSizeHigh;
            public uint nFileSizeLow;
            public uint dwReserved0;
            public uint dwReserved1;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]
            public string cFileName;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 14)]
            public string cAlternateFileName;
        }

        [Flags()]

        enum SLR_FLAGS
        {
            /// <summary>
            /// Do not display a dialog box if the link cannot be resolved. When SLR_NO_UI is set,
            /// the high-order word of fFlags can be set to a time-out value that specifies the
            /// maximum amount of time to be spent resolving the link. The function returns if the
            /// link cannot be resolved within the time-out duration. If the high-order word is set
            /// to zero, the time-out duration will be set to the default value of 3,000 milliseconds
            /// (3 seconds). To specify a value, set the high word of fFlags to the desired time-out
            /// duration, in milliseconds.
            /// </summary>
            SLR_NO_UI = 0x1,
            /// <summary>Obsolete and no longer used</summary>
            SLR_ANY_MATCH = 0x2,
            /// <summary>If the link object has changed, update its path and list of identifiers.
            /// If SLR_UPDATE is set, you do not need to call IPersistFile::IsDirty to determine
            /// whether or not the link object has changed.</summary>
            SLR_UPDATE = 0x4,
            /// <summary>Do not update the link information</summary>
            SLR_NOUPDATE = 0x8,
            /// <summary>Do not execute the search heuristics</summary>
            SLR_NOSEARCH = 0x10,
            /// <summary>Do not use distributed link tracking</summary>
            SLR_NOTRACK = 0x20,
            /// <summary>Disable distributed link tracking. By default, distributed link tracking tracks
            /// removable media across multiple devices based on the volume name. It also uses the
            /// Universal Naming Convention (UNC) path to track remote file systems whose drive letter
            /// has changed. Setting SLR_NOLINKINFO disables both types of tracking.</summary>
            SLR_NOLINKINFO = 0x40,
            /// <summary>Call the Microsoft Windows Installer</summary>
            SLR_INVOKE_MSI = 0x80
        }


        /// <summary>The IShellLink interface allows Shell links to be created, modified, and resolved</summary>
        [ComImport(), InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("000214F9-0000-0000-C000-000000000046")]
        interface IShellLinkW
        {
            /// <summary>Retrieves the path and file name of a Shell link object</summary>
            void GetPath([Out(), MarshalAs(UnmanagedType.LPWStr)] StringBuilder pszFile, int cchMaxPath, out WIN32_FIND_DATAW pfd, SLGP_FLAGS fFlags);
            /// <summary>Retrieves the list of item identifiers for a Shell link object</summary>
            void GetIDList(out IntPtr ppidl);
            /// <summary>Sets the pointer to an item identifier list (PIDL) for a Shell link object.</summary>
            void SetIDList(IntPtr pidl);
            /// <summary>Retrieves the description string for a Shell link object</summary>
            void GetDescription([Out(), MarshalAs(UnmanagedType.LPWStr)] StringBuilder pszName, int cchMaxName);
            /// <summary>Sets the description for a Shell link object. The description can be any application-defined string</summary>
            void SetDescription([MarshalAs(UnmanagedType.LPWStr)] string pszName);
            /// <summary>Retrieves the name of the working directory for a Shell link object</summary>
            void GetWorkingDirectory([Out(), MarshalAs(UnmanagedType.LPWStr)] StringBuilder pszDir, int cchMaxPath);
            /// <summary>Sets the name of the working directory for a Shell link object</summary>
            void SetWorkingDirectory([MarshalAs(UnmanagedType.LPWStr)] string pszDir);
            /// <summary>Retrieves the command-line arguments associated with a Shell link object</summary>
            void GetArguments([Out(), MarshalAs(UnmanagedType.LPWStr)] StringBuilder pszArgs, int cchMaxPath);
            /// <summary>Sets the command-line arguments for a Shell link object</summary>
            void SetArguments([MarshalAs(UnmanagedType.LPWStr)] string pszArgs);
            /// <summary>Retrieves the hot key for a Shell link object</summary>
            void GetHotkey(out short pwHotkey);
            /// <summary>Sets a hot key for a Shell link object</summary>
            void SetHotkey(short wHotkey);
            /// <summary>Retrieves the show command for a Shell link object</summary>
            void GetShowCmd(out int piShowCmd);
            /// <summary>Sets the show command for a Shell link object. The show command sets the initial show state of the window.</summary>
            void SetShowCmd(int iShowCmd);
            /// <summary>Retrieves the location (path and index) of the icon for a Shell link object</summary>
            void GetIconLocation([Out(), MarshalAs(UnmanagedType.LPWStr)] StringBuilder pszIconPath,
                int cchIconPath, out int piIcon);
            /// <summary>Sets the location (path and index) of the icon for a Shell link object</summary>
            void SetIconLocation([MarshalAs(UnmanagedType.LPWStr)] string pszIconPath, int iIcon);
            /// <summary>Sets the relative path to the Shell link object</summary>
            void SetRelativePath([MarshalAs(UnmanagedType.LPWStr)] string pszPathRel, int dwReserved);
            /// <summary>Attempts to find the target of a Shell link, even if it has been moved or renamed</summary>
            void Resolve(IntPtr hwnd, SLR_FLAGS fFlags);
            /// <summary>Sets the path and file name of a Shell link object</summary>
            void SetPath([MarshalAs(UnmanagedType.LPWStr)] string pszFile);

        }

        [ComImport, Guid("0000010c-0000-0000-c000-000000000046"),
        InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
        public interface IPersist
        {
            [PreserveSig]
            void GetClassID(out Guid pClassID);
        }


        [ComImport, Guid("0000010b-0000-0000-C000-000000000046"),
        InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
        public interface IPersistFile : IPersist
        {
            new void GetClassID(out Guid pClassID);
            [PreserveSig]
            int IsDirty();

            [PreserveSig]
            void Load([In, MarshalAs(UnmanagedType.LPWStr)]
            string pszFileName, uint dwMode);

            [PreserveSig]
            void Save([In, MarshalAs(UnmanagedType.LPWStr)] string pszFileName,
                [In, MarshalAs(UnmanagedType.Bool)] bool fRemember);

            [PreserveSig]
            void SaveCompleted([In, MarshalAs(UnmanagedType.LPWStr)] string pszFileName);

            [PreserveSig]
            void GetCurFile([In, MarshalAs(UnmanagedType.LPWStr)] string ppszFileName);
        }

        const uint STGM_READ = 0;
        const int MAX_PATH = 260;

        // CLSID_ShellLink from ShlGuid.h 
        [
            ComImport(),
            Guid("00021401-0000-0000-C000-000000000046")
        ]
        public class ShellLink
        {
        }

        #endregion 


        public static string ResolveShortcut(string filename)
        {
            ShellLink link = new ShellLink();
            ((IPersistFile)link).Load(filename, STGM_READ);
            // TODO: if I can get hold of the hwnd call resolve first. This handles moved and renamed files.  
            // ((IShellLinkW)link).Resolve(hwnd, 0) 
            StringBuilder sb = new StringBuilder(MAX_PATH);
            WIN32_FIND_DATAW data = new WIN32_FIND_DATAW();
            ((IShellLinkW)link).GetPath(sb, sb.Capacity, out data, 0);
            return sb.ToString(); 
        }
Sam Saffron
Thanks for the sample code. It worked an is very helpful for those who want to avoid the depency to IWshRuntimeLibrary.dll file.
Martin