下面是我用于IO任务的一个实用程序类。

using System;
using System.Runtime.InteropServices;

namespace MyNameSpace
{
    public class ShellFileOperation
    {
        private static String StringArrayToMultiString(String[] stringArray)
        {
            String multiString = "";

            if (stringArray == null)
                return "";

            for (int i=0 ; i<stringArray.Length ; i++)
                multiString += stringArray[i] + '\0';

            multiString += '\0';

            return multiString;
        }

        public static bool Copy(string source, string dest)
        {
            return Copy(new String[] { source }, new String[] { dest });
        }

        public static bool Copy(String[] source, String[] dest)
        {
            Win32.SHFILEOPSTRUCT FileOpStruct = new Win32.SHFILEOPSTRUCT();

            FileOpStruct.hwnd = IntPtr.Zero;
            FileOpStruct.wFunc = (uint)Win32.FO_COPY;

            String multiSource = StringArrayToMultiString(source);
            String multiDest = StringArrayToMultiString(dest);
            FileOpStruct.pFrom = Marshal.StringToHGlobalUni(multiSource);
            FileOpStruct.pTo = Marshal.StringToHGlobalUni(multiDest);

            FileOpStruct.fFlags = (ushort)Win32.ShellFileOperationFlags.FOF_NOCONFIRMATION;
            FileOpStruct.lpszProgressTitle = "";
            FileOpStruct.fAnyOperationsAborted = 0;
            FileOpStruct.hNameMappings = IntPtr.Zero;

            int retval = Win32.SHFileOperation(ref FileOpStruct);

            if(retval != 0) return false;
            return true;
        }

        public static bool Move(string source, string dest)
        {
            return Move(new String[] { source }, new String[] { dest });
        }

        public static bool Delete(string file)
        {
            Win32.SHFILEOPSTRUCT FileOpStruct = new Win32.SHFILEOPSTRUCT();

            FileOpStruct.hwnd = IntPtr.Zero;
            FileOpStruct.wFunc = (uint)Win32.FO_DELETE;

            String multiSource = StringArrayToMultiString(new string[] { file });
            FileOpStruct.pFrom = Marshal.StringToHGlobalUni(multiSource);
            FileOpStruct.pTo =  IntPtr.Zero;

            FileOpStruct.fFlags = (ushort)Win32.ShellFileOperationFlags.FOF_SILENT | (ushort)Win32.ShellFileOperationFlags.FOF_NOCONFIRMATION | (ushort)Win32.ShellFileOperationFlags.FOF_NOERRORUI | (ushort)Win32.ShellFileOperationFlags.FOF_NOCONFIRMMKDIR;
            FileOpStruct.lpszProgressTitle = "";
            FileOpStruct.fAnyOperationsAborted = 0;
            FileOpStruct.hNameMappings = IntPtr.Zero;

            int retval = Win32.SHFileOperation(ref FileOpStruct);

            if(retval != 0) return false;
            return true;
        }

        public static bool Move(String[] source, String[] dest)
        {
            Win32.SHFILEOPSTRUCT FileOpStruct = new Win32.SHFILEOPSTRUCT();

            FileOpStruct.hwnd = IntPtr.Zero;
            FileOpStruct.wFunc = (uint)Win32.FO_MOVE;

            String multiSource = StringArrayToMultiString(source);
            String multiDest = StringArrayToMultiString(dest);
            FileOpStruct.pFrom = Marshal.StringToHGlobalUni(multiSource);
            FileOpStruct.pTo = Marshal.StringToHGlobalUni(multiDest);

            FileOpStruct.fFlags = (ushort)Win32.ShellFileOperationFlags.FOF_NOCONFIRMATION;
            FileOpStruct.lpszProgressTitle = "";
            FileOpStruct.fAnyOperationsAborted = 0;
            FileOpStruct.hNameMappings = IntPtr.Zero;

            int retval = Win32.SHFileOperation(ref FileOpStruct);

            if(retval != 0) return false;
            return true;
        }
    }
}

对于d4nt的答案有一个小的改进，因为如果你在服务器和开发机器上工作，你可能想检查错误，而不必更改xcopy路径:

public void CopyFolder(string source, string destination)
{
    string xcopyPath = Environment.GetEnvironmentVariable("WINDIR") + @"\System32\xcopy.exe";
    ProcessStartInfo info = new ProcessStartInfo(xcopyPath);
    info.UseShellExecute = false;
    info.RedirectStandardOutput = true;
    info.Arguments = string.Format("\"{0}\" \"{1}\" /E /I", source, destination);

    Process process = Process.Start(info);
    process.WaitForExit();
    string result = process.StandardOutput.ReadToEnd();

    if (process.ExitCode != 0)
    {
        // Or your own custom exception, or just return false if you prefer.
        throw new InvalidOperationException(string.Format("Failed to copy {0} to {1}: {2}", source, destination, result));
    }
}

只是想加上我的版本。它可以处理目录和文件，如果目标文件存在，则可以覆盖或跳过。

public static void Copy(
    string source,
    string destination,
    string pattern = "*",
    bool includeSubFolders = true,
    bool overwrite = true,
    bool overwriteOnlyIfSourceIsNewer = false)
{
    if (File.Exists(source))
    {
        // Source is a file, copy and leave
        CopyFile(source, destination);
        return;
    }

    if (!Directory.Exists(source))
    {
        throw new DirectoryNotFoundException($"Source directory does not exists: `{source}`");
    }

    var files = Directory.GetFiles(
        source,
        pattern,
        includeSubFolders ?
            SearchOption.AllDirectories :
            SearchOption.TopDirectoryOnly);

    foreach (var file in files)
    {
        var newFile = file.Replace(source, destination);
        CopyFile(file, newFile, overwrite, overwriteOnlyIfSourceIsNewer);
    }
}

private static void CopyFile(
    string source,
    string destination,
    bool overwrite = true,
    bool overwriteIfSourceIsNewer = false)
{
    if (!overwrite && File.Exists(destination))
    {
        return;
    }

    if (overwriteIfSourceIsNewer && File.Exists(destination))
    {
        var sourceLastModified = File.GetLastWriteTimeUtc(source);
        var destinationLastModified = File.GetLastWriteTimeUtc(destination);
        if (sourceLastModified <= destinationLastModified)
        {
            return;
        }

        CreateDirectory(destination);
        File.Copy(source, destination, overwrite);
        return;
    }

    CreateDirectory(destination);
    File.Copy(source, destination, overwrite);
}

private static void CreateDirectory(string filePath)
{
    var targetDirectory = Path.GetDirectoryName(filePath);
    if (targetDirectory != null && !Directory.Exists(targetDirectory))
    {
        Directory.CreateDirectory(targetDirectory);
    }
}

或者，如果你想走一条艰难的路，为你的微软项目添加一个引用。然后使用下面的代码:

Microsoft.VisualBasic.FileIO.FileSystem.CopyDirectory(fromDirectory, toDirectory);

然而，使用一个递归函数是一个更好的方法，因为它不需要加载VB dll。

这是我的代码，希望对大家有所帮助

    private void KCOPY(string source, string destination)
    {
        if (IsFile(source))
        {
            string target = Path.Combine(destination, Path.GetFileName(source));
            File.Copy(source, target, true);
        }
        else
        {
            string fileName = Path.GetFileName(source);
            string target = System.IO.Path.Combine(destination, fileName);
            if (!System.IO.Directory.Exists(target))
            {
                System.IO.Directory.CreateDirectory(target);
            }

            List<string> files = GetAllFileAndFolder(source);

            foreach (string file in files)
            {
                KCOPY(file, target);
            }
        }
    }

    private List<string> GetAllFileAndFolder(string path)
    {
        List<string> allFile = new List<string>();
        foreach (string dir in Directory.GetDirectories(path))
        {
            allFile.Add(dir);
        }
        foreach (string file in Directory.GetFiles(path))
        {
            allFile.Add(file);
        }

        return allFile;
    }
    private bool IsFile(string path)
    {
        if ((File.GetAttributes(path) & FileAttributes.Directory) == FileAttributes.Directory)
        {
            return false;
        }
        return true;
    }

嗯，我想我误解了这个问题，但我要冒这个险。下面这个简单的方法有什么问题?

public static void CopyFilesRecursively(DirectoryInfo source, DirectoryInfo target) {
    foreach (DirectoryInfo dir in source.GetDirectories())
        CopyFilesRecursively(dir, target.CreateSubdirectory(dir.Name));
    foreach (FileInfo file in source.GetFiles())
        file.CopyTo(Path.Combine(target.FullName, file.Name));
}

由于这篇文章为一个同样简单的问题提供了如此简单的答案，获得了令人印象深刻的反对票，让我补充一个解释。请在投反对票前阅读这篇文章。

首先，这段代码并不打算作为问题中代码的直接替换。这只是为了说明。

microsoft . visualbasic . devices . computer . filesystm . copydirectory执行一些附加的正确性测试(例如，源和目标是否为有效目录，源是否为目标的父目录等)，这些测试在这个答案中是缺失的。该代码可能也更加优化了。

也就是说，代码运行良好。它(几乎完全相同)已经在一个成熟的软件中使用多年了。除了所有IO处理固有的变化无常(例如，如果用户在代码写入USB驱动器时手动拔出USB驱动器会发生什么?)，没有已知的问题。

特别地，我想指出这里使用递归绝对不是问题。无论是在理论上(概念上，这是最优雅的解决方案)还是在实践中:这段代码都不会溢出堆栈。这个堆栈足够大，甚至可以处理嵌套很深的文件层次结构。早在堆栈空间成为问题之前，文件夹路径长度限制就开始生效了。

请注意，恶意用户可能会通过使用每个字母嵌套很深的目录来打破这一假设。我还没试过。但是为了说明这一点:为了使这段代码在典型的计算机上溢出，目录必须嵌套几千次。这是不现实的情况。