我想在.NET 中使用 NTFS 压缩来压缩文件夹。我找到了这篇文章,但它不起作用。它抛出异常(“无效参数”)。
DirectoryInfo directoryInfo = new DirectoryInfo( destinationDir );
if( ( directoryInfo.Attributes & FileAttributes.Compressed ) != FileAttributes.Compressed )
{
string objPath = "Win32_Directory.Name=" + "\"" + destinationDir + "\"";
using( ManagementObject dir = new ManagementObject( objPath ) )
{
ManagementBaseObject outParams = dir.InvokeMethod( "Compress", null, null );
uint ret = (uint)( outParams.Properties["ReturnValue"].Value );
}
}
有人知道如何在文件夹上启用 NTFS 压缩吗?
根据我的经验,使用 P/Invoke 通常比 WMI 更容易。我相信以下应该有效:
private const int FSCTL_SET_COMPRESSION = 0x9C040;
private const short COMPRESSION_FORMAT_DEFAULT = 1;
[DllImport("kernel32.dll", SetLastError = true)]
private static extern int DeviceIoControl(
SafeFileHandle hDevice,
int dwIoControlCode,
ref short lpInBuffer,
int nInBufferSize,
IntPtr lpOutBuffer,
int nOutBufferSize,
ref int lpBytesReturned,
IntPtr lpOverlapped);
public static bool EnableCompression(SafeFileHandle handle)
{
int lpBytesReturned = 0;
short lpInBuffer = COMPRESSION_FORMAT_DEFAULT;
return DeviceIoControl(handle, FSCTL_SET_COMPRESSION,
ref lpInBuffer, sizeof(short), IntPtr.Zero, 0,
ref lpBytesReturned, IntPtr.Zero) != 0;
}
由于您尝试在目录上设置此选项,因此您可能需要使用 P/Invoke 来调用 CreateFile,使用
FILE_FLAG_BACKUP_SEMANTICS
来获取目录上的 SafeFileHandle。
另请注意,在 NTFS 中的目录上设置压缩不会压缩所有内容,它只会使新文件显示为压缩的(加密也是如此)。如果要压缩整个目录,则需要遍历整个目录并对每个文件/文件夹调用 DeviceIoControl。
我已经测试了代码,它
(来源:typepad.com)
!
完整代码:
using System.IO;
using System.Management;
class Program
{
static void Main(string[] args)
{
string destinationDir = "c:/temp/testcomp";
DirectoryInfo directoryInfo = new DirectoryInfo(destinationDir);
if ((directoryInfo.Attributes & FileAttributes.Compressed) != FileAttributes.Compressed)
{
string objPath = "Win32_Directory.Name=" + "'" + directoryInfo.FullName.Replace("\\", @"\\").TrimEnd('\\') + "'";
using (ManagementObject dir = new ManagementObject(objPath))
{
ManagementBaseObject outParams = dir.InvokeMethod("Compress", null, null);
uint ret = (uint)(outParams.Properties["ReturnValue"].Value);
}
}
}
}
有一种更简单的方法,我在 Windows 8 64 位中使用,为 VB.NET 重写。享受吧。
Dim Path as string = "c:\test"
Dim strComputer As String = "."
Dim objWMIService = GetObject("winmgmts:{impersonationLevel=impersonate}!\\.\root\cimv2")
Dim colFolders = objWMIService.ExecQuery("Select * from Win32_Directory where name = '" & Replace(path, "\", "\\") & "'")
For Each objFolder In colFolders
objFolder.Compress()
Next
对我来说非常有用。查涅。 oot 到 \pcname oot 如果您需要在另一台计算机上执行此操作。小心使用。
创建 Win32_Directory.Name=... 字符串时,您需要双反斜杠,因此例如路径 C:\Foo\Bar 将构建为:
Win32_Directory.Name =“C:\ Foo \ Bar”,
或使用您的示例代码:
string objPath = "Win32_Directory.Name=\"C:\\Foo\\Bar\"";
显然,该字符串被馈送到某个需要路径字符串转义形式的进程。
这是对 Igal Serban 答案的轻微改编。我遇到了一个微妙的问题,
Name
必须采用非常特定的格式。所以我首先添加了一些 Replace("\\", @"\\").TrimEnd('\\')
magic 来标准化路径,我还清理了一些代码。
var dir = new DirectoryInfo(_outputFolder);
if (!dir.Exists)
{
dir.Create();
}
if ((dir.Attributes & FileAttributes.Compressed) == 0)
{
try
{
// Enable compression for the output folder
// (this will save a ton of disk space)
string objPath = "Win32_Directory.Name=" + "'" + dir.FullName.Replace("\\", @"\\").TrimEnd('\\') + "'";
using (ManagementObject obj = new ManagementObject(objPath))
{
using (obj.InvokeMethod("Compress", null, null))
{
// I don't really care about the return value,
// if we enabled it great but it can also be done manually
// if really needed
}
}
}
catch (Exception ex)
{
System.Diagnostics.Trace.WriteLine("Cannot enable compression for folder '" + dir.FullName + "': " + ex.Message, "WMI");
}
}
我不相信有一种方法可以在 .NET 框架中设置文件夹压缩,因为文档(备注部分)声称它不能通过 File.SetAttributes 来完成。这似乎仅在使用 DeviceIoControl 函数的 Win32 API 中可用。人们仍然可以通过 .NET 使用 PInvoke 来完成此操作。
总体熟悉 PInvoke 后,请查看 pinvoke.net 上的参考资料,其中讨论了 signature 需要是什么样子才能实现这一点。
我根据 Zack Elan 的解决方案创建了
SafeFileHandle
,所以我在此处发布了整个课程以供参考:
internal class FileCompressor
{
private const int FSCTL_SET_COMPRESSION = 0x9C040;
private const short COMPRESSION_FORMAT_DEFAULT = 1;
private const uint GENERIC_ALL = 0x10000000;
private const uint OPEN_EXISTING = 3;
private const uint FILE_FLAG_BACKUP_SEMANTICS = 0x2000000;
[DllImport("kernel32.dll", SetLastError = true)]
private static extern int DeviceIoControl(SafeFileHandle hDevice, int dwIoControlCode, ref short lpInBuffer,
int nInBufferSize, IntPtr lpOutBuffer, int nOutBufferSize, ref int lpBytesReturned, IntPtr lpOverlapped);
[DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
static extern SafeFileHandle CreateFile(string lpFileName, uint dwDesiredAccess, uint dwShareMode,
IntPtr lpSecurityAttributes, uint dwCreationDisposition, uint dwFlagsAndAttributes, IntPtr hTemplateFile);
public void CompressFile(string path)
{
using SafeFileHandle handle = CreateFile(path, GENERIC_ALL, 0, IntPtr.Zero, OPEN_EXISTING,
FILE_FLAG_BACKUP_SEMANTICS, IntPtr.Zero);
if (!EnableCompression(handle))
{
// Handle error
}
}
private static bool EnableCompression(SafeFileHandle handle)
{
int lpBytesReturned = 0;
short lpInBuffer = COMPRESSION_FORMAT_DEFAULT;
return DeviceIoControl(handle, FSCTL_SET_COMPRESSION, ref lpInBuffer, sizeof(short), IntPtr.Zero, 0,
ref lpBytesReturned, IntPtr.Zero) != 0;
}
}