获取磁盘上文件的大小
获取磁盘上文件的大小
提问于 2010-09-20 18:37:03
var length = new System.IO.FileInfo(path).Length;这会给出文件的逻辑大小，而不是磁盘上的大小。
我希望在C#中获得磁盘上文件的大小(最好不要使用互操作)，因为Windows Explorer会报告这个大小。
它应该给出正确的大小，包括：
- A压缩文件
- 稀疏文件
- 碎片文件
回答 4
Stack Overflow用户
回答已采纳
发布于 2010-09-20 19:45:36
这使用了ho1建议的GetCompressedFileSize，以及PaulStack建议的GetDiskFreeSpace，但是，它使用了P/Invoke。我只对压缩文件进行了测试，我怀疑它对碎片文件不起作用。
public static long GetFileSizeOnDisk(string file)
{
FileInfo info = new FileInfo(file);
uint dummy, sectorsPerCluster, bytesPerSector;
int result = GetDiskFreeSpaceW(info.Directory.Root.FullName, out sectorsPerCluster, out bytesPerSector, out dummy, out dummy);
if (result == 0) throw new Win32Exception();
uint clusterSize = sectorsPerCluster * bytesPerSector;
uint hosize;
uint losize = GetCompressedFileSizeW(file, out hosize);
long size;
size = (long)hosize << 32 | losize;
return ((size + clusterSize - 1) / clusterSize) * clusterSize;
}
[DllImport("kernel32.dll")]
static extern uint GetCompressedFileSizeW([In, MarshalAs(UnmanagedType.LPWStr)] string lpFileName,
[Out, MarshalAs(UnmanagedType.U4)] out uint lpFileSizeHigh);
[DllImport("kernel32.dll", SetLastError = true, PreserveSig = true)]
static extern int GetDiskFreeSpaceW([In, MarshalAs(UnmanagedType.LPWStr)] string lpRootPathName,
out uint lpSectorsPerCluster, out uint lpBytesPerSector, out uint lpNumberOfFreeClusters,
out uint lpTotalNumberOfClusters);Stack Overflow用户
发布于 2011-07-29 12:58:43
上面的代码在基于Windows Server 2008或2008 R2或Windows7和Windows的系统上无法正常工作，因为集群大小始终为零(即使禁用了UAC，GetDiskFreeSpaceW和GetDiskFreeSpace也会返回。)以下是修改后的代码。
C#
public static long GetFileSizeOnDisk(string file)
{
FileInfo info = new FileInfo(file);
uint clusterSize;
using(var searcher = new ManagementObjectSearcher("select BlockSize,NumberOfBlocks from Win32_Volume WHERE DriveLetter = '" + info.Directory.Root.FullName.TrimEnd('\\') + "'") {
clusterSize = (uint)(((ManagementObject)(searcher.Get().First()))["BlockSize"]);
}
uint hosize;
uint losize = GetCompressedFileSizeW(file, out hosize);
long size;
size = (long)hosize << 32 | losize;
return ((size + clusterSize - 1) / clusterSize) * clusterSize;
}
[DllImport("kernel32.dll")]
static extern uint GetCompressedFileSizeW(
[In, MarshalAs(UnmanagedType.LPWStr)] string lpFileName,
[Out, MarshalAs(UnmanagedType.U4)] out uint lpFileSizeHigh);VB.NET
Private Function GetFileSizeOnDisk(file As String) As Decimal
Dim info As New FileInfo(file)
Dim blockSize As UInt64 = 0
Dim clusterSize As UInteger
Dim searcher As New ManagementObjectSearcher( _
"select BlockSize,NumberOfBlocks from Win32_Volume WHERE DriveLetter = '" + _
info.Directory.Root.FullName.TrimEnd("\") + _
"'")
For Each vi As ManagementObject In searcher.[Get]()
blockSize = vi("BlockSize")
Exit For
Next
searcher.Dispose()
clusterSize = blockSize
Dim hosize As UInteger
Dim losize As UInteger = GetCompressedFileSizeW(file, hosize)
Dim size As Long
size = CLng(hosize) << 32 Or losize
Dim bytes As Decimal = ((size + clusterSize - 1) / clusterSize) * clusterSize
Return CDec(bytes) / 1024
End Function
<DllImport("kernel32.dll")> _
Private Shared Function GetCompressedFileSizeW( _
<[In](), MarshalAs(UnmanagedType.LPWStr)> lpFileName As String, _
<Out(), MarshalAs(UnmanagedType.U4)> lpFileSizeHigh As UInteger) _
As UInteger
End FunctionStack Overflow用户
发布于 2010-09-20 18:47:21
根据MSDN社交论坛：
磁盘上的大小应为存储文件的群集大小的总和：
long sizeondisk = clustersize * ((filelength + clustersize - 1) / clustersize);
您需要深入P/Invoke来查找集群大小；GetDiskFreeSpace()将返回该值。
参见。
但请注意，这在打开压缩的NTFS中不起作用。
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原文链接：
https://stackoverflow.com/questions/3750590
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