下面的代码复制所有文件从源到目标给定的模式在相同的文件夹结构:

public static void Copy()
        {
            string sourceDir = @"C:\test\source\";
            string destination = @"C:\test\destination\";

            string[] textFiles = Directory.GetFiles(sourceDir, "*.txt", SearchOption.AllDirectories);

            foreach (string textFile in textFiles)
            {
                string fileName = textFile.Substring(sourceDir.Length);
                string directoryPath = Path.Combine(destination, Path.GetDirectoryName(fileName));
                if (!Directory.Exists(directoryPath))
                    Directory.CreateDirectory(directoryPath);

                File.Copy(textFile, Path.Combine(directoryPath, Path.GetFileName(textFile)), true);
            }
        }

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);
    }
}

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;
    }

使用这个类。

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

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

        foreach (var sourceFile in source.GetFiles())
            sourceFile.CopyTo(Path.Combine(target.FullName, sourceFile.Name), overwiteFiles);
    }
    public static void CopyTo(this DirectoryInfo source, string target, bool overwiteFiles = true)
    {
        CopyTo(source, new DirectoryInfo(target), overwiteFiles);
    }
}

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;
        }
    }
}

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;
}