最近，我一直在尝试实现一些从InfoPath XSN文件（.CAB存档）中提取文件的功能。在广泛搜索互联网之后，似乎没有本地.NET API。所有当前的解决方案都围绕着大型库，即托管的C ++，它包含了Cabinet.dll。
遗憾的是，所有这些都违反了我的公司“没有第三方图书馆”的政策。
从2.0开始，.NET获得了一个名为UnmanagedFunctionPointer的属性，该属性允许使用__cdecl进行源级回调声明。在此之前，__ stdcall是镇上唯一的节目，除非你不介意捏造IL，这种做法在这里也是非法的。我立即知道这将允许为Cabinet.dll实现一个相当小的C＃包装器，但我找不到任何地方的例子。
有没有人知道使用本机代码执行此操作的方法比以下更简洁？
我当前的解决方案（执行非托管代码，但完全正常，在32/64位上测试）：
[StructLayout(LayoutKind.Sequential)]
public class CabinetInfo //Cabinet API: "FDCABINETINFO"
{
public int cbCabinet;
public short cFolders;
public short cFiles;
public short setID;
public short iCabinet;
public int fReserve;
public int hasprev;
public int hasnext;
}
public class CabExtract : IDisposable
{
//If any of these classes end up with a different size to its C equivilent, we end up with crash and burn.
[StructLayout(LayoutKind.Sequential)]
private class CabError //Cabinet API: "ERF"
{
public int erfOper;
public int erfType;
public int fError;
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
private class FdiNotification //Cabinet API: "FDINOTIFICATION"
{
public int cb;
public string psz1;
public string psz2;
public string psz3;
public IntPtr userData;
public IntPtr hf;
public short date;
public short time;
public short attribs;
public short setID;
public short iCabinet;
public short iFolder;
public int fdie;
}
private enum FdiNotificationType
{
CabinetInfo,
PartialFile,
CopyFile,
CloseFileInfo,
NextCabinet,
Enumerate
}
private class DecompressFile
{
public IntPtr Handle { get; set; }
public string Name { get; set; }
public bool Found { get; set; }
public int Length { get; set; }
public byte[] Data { get; set; }
}
[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
private delegate IntPtr FdiMemAllocDelegate(int numBytes);
[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
private delegate void FdiMemFreeDelegate(IntPtr mem);
[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
private delegate IntPtr FdiFileOpenDelegate(string fileName, int oflag, int pmode);
[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
private delegate Int32 FdiFileReadDelegate(IntPtr hf,
[In, Out] [MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 2,
ArraySubType = UnmanagedType.U1)] byte[] buffer, int cb);
[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
private delegate Int32 FdiFileWriteDelegate(IntPtr hf,
[In] [MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 2,
ArraySubType = UnmanagedType.U1)] byte[] buffer, int cb);
[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
private delegate Int32 FdiFileCloseDelegate(IntPtr hf);
[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
private delegate Int32 FdiFileSeekDelegate(IntPtr hf, int dist, int seektype);
[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
private delegate IntPtr FdiNotifyDelegate(
FdiNotificationType fdint, [In] [MarshalAs(UnmanagedType.LPStruct)] FdiNotification fdin);
[DllImport("cabinet.dll", CallingConvention = CallingConvention.Cdecl, EntryPoint = "FDICreate", CharSet = CharSet.Ansi)]
private static extern IntPtr FdiCreate(
FdiMemAllocDelegate fnMemAlloc,
FdiMemFreeDelegate fnMemFree,
FdiFileOpenDelegate fnFileOpen,
FdiFileReadDelegate fnFileRead,
FdiFileWriteDelegate fnFileWrite,
FdiFileCloseDelegate fnFileClose,
FdiFileSeekDelegate fnFileSeek,
int cpuType,
[MarshalAs(UnmanagedType.LPStruct)] CabError erf);
[DllImport("cabinet.dll", CallingConvention = CallingConvention.Cdecl, EntryPoint = "FDIIsCabinet", CharSet = CharSet.Ansi)]
private static extern bool FdiIsCabinet(
IntPtr hfdi,
IntPtr hf,
[MarshalAs(UnmanagedType.LPStruct)] CabinetInfo cabInfo);
[DllImport("cabinet.dll", CallingConvention = CallingConvention.Cdecl, EntryPoint = "FDIDestroy", CharSet = CharSet.Ansi)]
private static extern bool FdiDestroy(IntPtr hfdi);
[DllImport("cabinet.dll", CallingConvention = CallingConvention.Cdecl, EntryPoint = "FDICopy", CharSet = CharSet.Ansi)]
private static extern bool FdiCopy(
IntPtr hfdi,
string cabinetName,
string cabinetPath,
int flags,
FdiNotifyDelegate fnNotify,
IntPtr fnDecrypt,
IntPtr userData);
private readonly FdiFileCloseDelegate _fileCloseDelegate;
private readonly FdiFileOpenDelegate _fileOpenDelegate;
private readonly FdiFileReadDelegate _fileReadDelegate;
private readonly FdiFileSeekDelegate _fileSeekDelegate;
private readonly FdiFileWriteDelegate _fileWriteDelegate;
private readonly FdiMemAllocDelegate _femAllocDelegate;
private readonly FdiMemFreeDelegate _memFreeDelegate;
private readonly CabError _erf;
private readonly List<DecompressFile> _decompressFiles;
private readonly byte[] _inputData;
private IntPtr _hfdi;
private bool _disposed;
private const int CpuTypeUnknown = -1;
public CabExtract(byte[] inputData)
{
_fileReadDelegate = FileRead;
_fileOpenDelegate = InputFileOpen;
_femAllocDelegate = MemAlloc;
_fileSeekDelegate = FileSeek;
_memFreeDelegate = MemFree;
_fileWriteDelegate = FileWrite;
_fileCloseDelegate = InputFileClose;
_inputData = inputData;
_decompressFiles = new List<DecompressFile>();
_erf = new CabError();
_hfdi = IntPtr.Zero;
}
private static IntPtr FdiCreate(
FdiMemAllocDelegate fnMemAlloc,
FdiMemFreeDelegate fnMemFree,
FdiFileOpenDelegate fnFileOpen,
FdiFileReadDelegate fnFileRead,
FdiFileWriteDelegate fnFileWrite,
FdiFileCloseDelegate fnFileClose,
FdiFileSeekDelegate fnFileSeek,
CabError erf)
{
return FdiCreate(fnMemAlloc, fnMemFree, fnFileOpen, fnFileRead, fnFileWrite,
fnFileClose, fnFileSeek, CpuTypeUnknown, erf);
}
private static bool FdiCopy(
IntPtr hfdi,
FdiNotifyDelegate fnNotify)
{
return FdiCopy(hfdi, "<notused>", "<notused>", 0, fnNotify, IntPtr.Zero, IntPtr.Zero);
}
private IntPtr FdiContext
{
get
{
if (_hfdi == IntPtr.Zero)
{
_hfdi = FdiCreate(_femAllocDelegate, _memFreeDelegate, _fileOpenDelegate, _fileReadDelegate, _fileWriteDelegate, _fileCloseDelegate, _fileSeekDelegate, _erf);
if (_hfdi == IntPtr.Zero)
throw new ApplicationException("Failed to create FDI context.");
}
return _hfdi;
}
}
public void Dispose()
{
Dispose(true);
}
private void Dispose(bool disposing)
{
if (!_disposed)
{
if (_hfdi != IntPtr.Zero)
{
FdiDestroy(_hfdi);
_hfdi = IntPtr.Zero;
}
_disposed = true;
}
}
private IntPtr NotifyCallback(FdiNotificationType fdint, FdiNotification fdin)
{
switch (fdint)
{
case FdiNotificationType.CopyFile:
return OutputFileOpen(fdin);
case FdiNotificationType.CloseFileInfo:
return OutputFileClose(fdin);
default:
return IntPtr.Zero;
}
}
private IntPtr InputFileOpen(string fileName, int oflag, int pmode)
{
var stream = new MemoryStream(_inputData);
GCHandle gch = GCHandle.Alloc(stream);
return (IntPtr)gch;
}
private int InputFileClose(IntPtr hf)
{
var stream = StreamFromHandle(hf);
stream.Close();
((GCHandle)(hf)).Free();
return 0;
}
private IntPtr OutputFileOpen(FdiNotification fdin)
{
var extractFile = _decompressFiles.Where(ef => ef.Name == fdin.psz1).SingleOrDefault();
if (extractFile != null)
{
var stream = new MemoryStream();
GCHandle gch = GCHandle.Alloc(stream);
extractFile.Handle = (IntPtr)gch;
return extractFile.Handle;
}
//Don't extract
return IntPtr.Zero;
}
private IntPtr OutputFileClose(FdiNotification fdin)
{
var extractFile = _decompressFiles.Where(ef => ef.Handle == fdin.hf).Single();
var stream = StreamFromHandle(fdin.hf);
extractFile.Found = true;
extractFile.Length = (int)stream.Length;
if (stream.Length > 0)
{
extractFile.Data = new byte[stream.Length];
stream.Position = 0;
stream.Read(extractFile.Data, 0, (int)stream.Length);
}
stream.Close();
return IntPtr.Zero;
}
private int FileRead(IntPtr hf, byte[] buffer, int cb)
{
var stream = StreamFromHandle(hf);
return stream.Read(buffer, 0, cb);
}
private int FileWrite(IntPtr hf, byte[] buffer, int cb)
{
var stream = StreamFromHandle(hf);
stream.Write(buffer, 0, cb);
return cb;
}
private static Stream StreamFromHandle(IntPtr hf)
{
return (Stream)((GCHandle)hf).Target;
}
private IntPtr MemAlloc(int cb)
{
return Marshal.AllocHGlobal(cb);
}
private void MemFree(IntPtr mem)
{
Marshal.FreeHGlobal(mem);
}
private int FileSeek(IntPtr hf, int dist, int seektype)
{
var stream = StreamFromHandle(hf);
return (int)stream.Seek(dist, (SeekOrigin)seektype);
}
public bool ExtractFile(string fileName, out byte[] outputData, out int outputLength)
{
if (_disposed)
throw new ObjectDisposedException("CabExtract");
var fileToDecompress = new DecompressFile();
fileToDecompress.Found = false;
fileToDecompress.Name = fileName;
_decompressFiles.Add(fileToDecompress);
FdiCopy(FdiContext, NotifyCallback);
if (fileToDecompress.Found)
{
outputData = fileToDecompress.Data;
outputLength = fileToDecompress.Length;
_decompressFiles.Remove(fileToDecompress);
return true;
}
outputData = null;
outputLength = 0;
return false;
}
public bool IsCabinetFile(out CabinetInfo cabinfo)
{
if (_disposed)
throw new ObjectDisposedException("CabExtract");
var stream = new MemoryStream(_inputData);
GCHandle gch = GCHandle.Alloc(stream);
try
{
var info = new CabinetInfo();
var ret = FdiIsCabinet(FdiContext, (IntPtr)gch, info);
cabinfo = info;
return ret;
}
finally
{
stream.Close();
gch.Free();
}
}
public static bool IsCabinetFile(byte[] inputData, out CabinetInfo cabinfo)
{
using (var decomp = new CabExtract(inputData))
{
return decomp.IsCabinetFile(out cabinfo);
}
}
//In an ideal world, this would take a stream, but Cabinet.dll seems to want to open the input several times.
public static bool ExtractFile(byte[] inputData, string fileName, out byte[] outputData, out int length)
{
using (var decomp = new CabExtract(inputData))
{
return decomp.ExtractFile(fileName, out outputData, out length);
}
}
//TODO: Add methods for enumerating/extracting multiple files
}
答案 0 :(得分：1)
您是否可以使用Microsoft创建的其他库？它没有框架，但有一个用于处理Cab文件的MS库：
Microsoft.Deployment.Compression.Cab
可以使用如下
CabInfo cab = new CabInfo(@"C:\data.cab");
cab.Unpack(@"C:\ExtractDir");
答案 1 :(得分：0)
我们也有“没有第三方图书馆”的政策（很痛苦）。然而，出于各种原因，我们需要“展开”IP表格。我们的解决方案是使用CABARC（这是一个来自Microsoft的exe，它曾经包含在Windows安装中，尽管可能不再存在）。它可以用shell编写任何语言，我们使用vbs或powershell。它就像任何带命令行开关的zip / unzip程序一样工作。
对于那些从上面找到好消息的人来说，这只是另一种选择。
答案 2 :(得分：0)
扩展CAB文件与扩展ZIP文件相同。
您可以找到一些代码here
答案 3 :(得分：0)
这种方法怎么样： How to extract a file from a .CAB file? 我指的是JohnWein（MCC）的提案。 然后你用文件做什么 - 无论你是在目标直接文件中复制它们，如在引用示例的foreach状态中，还是只在内存中使用它们 - 取决于你。 （我想这也是 Alexandru-Dan 的意思 - 如果你不是在看问题而是在那里找到答案。）
如果这种方法在您的方案中有效，那么这是一个更简单的解决方案 - 没有任何第三方DLL。
是吗？
答案 4 :(得分：0)
如果关注第三方二进制库，我无能为力，但有开源ZIP库可以打开CAB文件。