C#获取大型目录的文件名和上次写入时间

Question

使用C#(.NET 2.0),在网络目录中检索文件列表的最佳方法是什么,优先选择按上次写入时间排序,还是根据上次写入时间排除返回值？

我目前正在使用DirectoryInfo实例的GetFiles方法返回一个列表.我遇到的目录可以包含超过6,000个文件,只需要获取一个FileInfo数组就需要大约25秒.

WMI不起作用,我看不到任何其他以.NET为中心的东西,这将有助于这种情况.我错过了什么吗？有没有比使用GetFiles更好的解决方案？

谢谢.

Answer 1

更新
我刚刚注意到这个旧的答案,对于.net 4.0及更高版本,有一种System.IO.EnumerateFiles方法可以为您执行此操作,对于.net 4.0之前的所有内容,请继续阅读.

.Net 3.5及早期

我和Stefan在一起,遇到了这个确切的问题,并推出了我自己的枚举器,用+ 100k文件迭代文件夹.

这个类包含了使用FindFirstFile和FindNextFile所需的所有API特定内容.

希望这可以帮助,

internal class APIWrapper
{
    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    internal sealed class FILETIME
    {
        public int Low;
        public int High;
        public Int64 ToInt64()
        {
            Int64 h = High;

            h = h << 32;
            return h + Low;
        }
    }


    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
    internal sealed class FindData
    {
        public int fileAttributes;
        public FILETIME CreationTime;
        public FILETIME LastAccessTime;
        public FILETIME LastWriteTime;
        public int FileSizeHigh;
        public int FileSizeLow;
        public int dwReserved0;
        public int dwReserved1;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]
        public String fileName;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 14)]
        public String alternateFileName;
    }
    internal sealed class SafeFindHandle : Microsoft.Win32.SafeHandles.SafeHandleMinusOneIsInvalid
    {
        /// <summary>
        /// Constructor
        /// </summary>
        public SafeFindHandle()
            : base(true)
        {
        }

        /// <summary>
        /// Release the find handle
        /// </summary>
        /// <returns>true if the handle was released</returns>
        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
        protected override bool ReleaseHandle()
        {
            return SafeNativeMethods.FindClose(handle);
        }
    }

    internal enum SearchOptions
    {
        NameMatch,
        LimitToDirectories,
        LimitToDevices
    }
    [SecurityPermissionAttribute(SecurityAction.Assert, UnmanagedCode = true)]
    internal static class SafeNativeMethods
    {
        [DllImport("Kernel32.dll", CharSet = CharSet.Auto)]
        public static extern SafeFindHandle FindFirstFile(String fileName, [In, Out] FindData findFileData);

        [DllImport("Kernel32.dll", CharSet = CharSet.Auto)]
        public static extern SafeFindHandle FindFirstFileEx(
            String fileName,                    //__in        LPCTSTR lpFileName,
            [In] int infoLevel,                 //__in        FINDEX_INFO_LEVELS fInfoLevelId,
            [In, Out] FindData findFileData,    //__out       LPVOID lpFindFileData,
            [In, Out] SearchOptions SerchOps,             //__in        FINDEX_SEARCH_OPS fSearchOp,
            [In] int SearchFilter,              //__reserved  LPVOID lpSearchFilter,
            [In] int AdditionalFlags);          //__in        DWORD dwAdditionalFlags

        [DllImport("kernel32", CharSet = CharSet.Auto)]
        [return: MarshalAs(UnmanagedType.Bool)]
        public static extern bool FindNextFile(SafeFindHandle hFindFile, [In, Out] FindData lpFindFileData);

        [DllImport("kernel32", CharSet = CharSet.Auto)]
        [return: MarshalAs(UnmanagedType.Bool)]
        public static extern bool FindClose(IntPtr hFindFile);
    }
}