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。

我的解决方案基本上是对@Termininja的答案的修改，但我增强了一点，它似乎比公认的答案快5倍以上。

public static void CopyEntireDirectory(string path, string newPath)
{
    Parallel.ForEach(Directory.GetFileSystemEntries(path, "*", SearchOption.AllDirectories)
    ,(fileName) =>
    {
        string output = Regex.Replace(fileName, "^" + Regex.Escape(path), newPath);
        if (File.Exists(fileName))
        {
            Directory.CreateDirectory(Path.GetDirectoryName(output));
            File.Copy(fileName, output, true);
        }
        else
            Directory.CreateDirectory(output);
    });
}

编辑:将@Ahmed Sabry修改为完全并行foreach确实会产生更好的结果，但是代码使用递归函数，在某些情况下并不理想。

public static void CopyEntireDirectory(DirectoryInfo source, DirectoryInfo target, bool overwiteFiles = true)
{
    if (!source.Exists) return;
    if (!target.Exists) target.Create();

    Parallel.ForEach(source.GetDirectories(), (sourceChildDirectory) =>
        CopyEntireDirectory(sourceChildDirectory, new DirectoryInfo(Path.Combine(target.FullName, sourceChildDirectory.Name))));

    Parallel.ForEach(source.GetFiles(), sourceFile =>
        sourceFile.CopyTo(Path.Combine(target.FullName, sourceFile.Name), overwiteFiles));
}

public static class Extensions
{
    public static void Copy(this DirectoryInfo self, DirectoryInfo destination, bool recursively)
    {
        foreach (var file in self.GetFiles())
        {
            file.CopyTo(Path.Combine(destination.FullName, file.Name));
        }

        if (recursively)
        {
            foreach (var directory in self.GetDirectories())
            {
                directory.Copy(destination.CreateSubdirectory(directory.Name), recursively);
            }
        }
    }
}

使用示例:

var sourceDirectory = new DirectoryInfo(@"C:\source");
var destinationDirectory = new DirectoryInfo(@"C:\destination");

if (destinationDirectory.Exists == false)
{
    sourceDirectory.Copy(destinationDirectory, recursively: true);
}

容易得多

private static void CopyFilesRecursively(string sourcePath, string targetPath)
{
    //Now Create all of the directories
    foreach (string dirPath in Directory.GetDirectories(sourcePath, "*", SearchOption.AllDirectories))
    {
        Directory.CreateDirectory(dirPath.Replace(sourcePath, targetPath));
    }

    //Copy all the files & Replaces any files with the same name
    foreach (string newPath in Directory.GetFiles(sourcePath, "*.*",SearchOption.AllDirectories))
    {
        File.Copy(newPath, newPath.Replace(sourcePath, targetPath), true);
    }
}

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;
        }
    }
}

比任何代码都好(使用递归扩展DirectoryInfo的方法)

public static bool CopyTo(this DirectoryInfo source, string destination)
    {
        try
        {
            foreach (string dirPath in Directory.GetDirectories(source.FullName))
            {
                var newDirPath = dirPath.Replace(source.FullName, destination);
                Directory.CreateDirectory(newDirPath);
                new DirectoryInfo(dirPath).CopyTo(newDirPath);
            }
            //Copy all the files & Replaces any files with the same name
            foreach (string filePath in Directory.GetFiles(source.FullName))
            {
                File.Copy(filePath, filePath.Replace(source.FullName,destination), true);
            }
            return true;
        }
        catch (IOException exp)
        {
            return false;
        }
    }