如果您喜欢Konrad的流行答案，但希望源代码本身是目标文件夹下的一个文件夹，而不是将它的子文件夹放在目标文件夹下，下面是实现该目的的代码。它返回新创建的DirectoryInfo，这很方便:

public static DirectoryInfo CopyFilesRecursively(DirectoryInfo source, DirectoryInfo target)
{
  var newDirectoryInfo = target.CreateSubdirectory(source.Name);
  foreach (var fileInfo in source.GetFiles())
    fileInfo.CopyTo(Path.Combine(newDirectoryInfo.FullName, fileInfo.Name));

  foreach (var childDirectoryInfo in source.GetDirectories())
    CopyFilesRecursively(childDirectoryInfo, newDirectoryInfo);

  return newDirectoryInfo;
}

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;
        }
    }
}

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;
    }

复制并替换文件夹中的所有文件

        public static void CopyAndReplaceAll(string SourcePath, string DestinationPath, string backupPath)
    {
            foreach (string dirPath in Directory.GetDirectories(SourcePath, "*", SearchOption.AllDirectories))
            {
                Directory.CreateDirectory($"{DestinationPath}{dirPath.Remove(0, SourcePath.Length)}");
                Directory.CreateDirectory($"{backupPath}{dirPath.Remove(0, SourcePath.Length)}");
            }
            foreach (string newPath in Directory.GetFiles(SourcePath, "*.*", SearchOption.AllDirectories))
            {
                if (!File.Exists($"{ DestinationPath}{newPath.Remove(0, SourcePath.Length)}"))
                    File.Copy(newPath, $"{ DestinationPath}{newPath.Remove(0, SourcePath.Length)}");
                else
                    File.Replace(newPath
                        , $"{ DestinationPath}{newPath.Remove(0, SourcePath.Length)}"
                        , $"{ backupPath}{newPath.Remove(0, SourcePath.Length)}", false);
            }
    }

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);
    }
}