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);
    }
}

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。

复制自MSDN:

using System;
using System.IO;

class CopyDir
{
    public static void Copy(string sourceDirectory, string targetDirectory)
    {
        DirectoryInfo diSource = new DirectoryInfo(sourceDirectory);
        DirectoryInfo diTarget = new DirectoryInfo(targetDirectory);

        CopyAll(diSource, diTarget);
    }

    public static void CopyAll(DirectoryInfo source, DirectoryInfo target)
    {
        Directory.CreateDirectory(target.FullName);

        // Copy each file into the new directory.
        foreach (FileInfo fi in source.GetFiles())
        {
            Console.WriteLine(@"Copying {0}\{1}", target.FullName, fi.Name);
            fi.CopyTo(Path.Combine(target.FullName, fi.Name), true);
        }

        // Copy each subdirectory using recursion.
        foreach (DirectoryInfo diSourceSubDir in source.GetDirectories())
        {
            DirectoryInfo nextTargetSubDir =
                target.CreateSubdirectory(diSourceSubDir.Name);
            CopyAll(diSourceSubDir, nextTargetSubDir);
        }
    }

    public static void Main()
    {
        string sourceDirectory = @"c:\sourceDirectory";
        string targetDirectory = @"c:\targetDirectory";

        Copy(sourceDirectory, targetDirectory);
    }

    // Output will vary based on the contents of the source directory.
}

抱歉之前的代码，它仍然有bug:((成为最快枪问题的猎物)。这里是测试和工作。键是SearchOption。AllDirectories，这消除了显式递归的需要。

string path = "C:\\a";
string[] dirs = Directory.GetDirectories(path, "*.*", SearchOption.AllDirectories);
string newpath = "C:\\x";
try
{
    Directory.CreateDirectory(newpath);
}
catch (IOException ex)
{
    Console.WriteLine(ex.Message);
}
for (int j = 0; j < dirs.Length; j++)
{
    try
    {
        Directory.CreateDirectory(dirs[j].Replace(path, newpath));
    }
    catch (IOException ex)
    {
        Console.WriteLine(ex.Message);
    }
}

string[] files = Directory.GetFiles(path, "*.*", SearchOption.AllDirectories);
for (int j = 0; j < files.Length; j++)            
{
    try
    {
        File.Copy(files[j], files[j].Replace(path, newpath));
    }
    catch (IOException ex)
    {
        Console.WriteLine(ex.Message);
    }
}

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);
}

这里有一个简洁而有效的解决方案:

namespace System.IO {
  public static class ExtensionMethods {

    public static void CopyTo(this DirectoryInfo srcPath, string destPath) {
      Directory.CreateDirectory(destPath);
      Parallel.ForEach(srcPath.GetDirectories("*", SearchOption.AllDirectories), 
        srcInfo => Directory.CreateDirectory($"{destPath}{srcInfo.FullName[srcPath.FullName.Length..]}"));
      Parallel.ForEach(srcPath.GetFiles("*", SearchOption.AllDirectories), 
        srcInfo => File.Copy(srcInfo.FullName, $"{destPath}{srcInfo.FullName[srcPath.FullName.Length..]}", true));
      });
    }

  }
}

使用方法:

new DirectoryInfo(sourcePath).CopyTo(destinationPath);