一个只有一个循环复制所有文件夹和文件的变体:

foreach (var f in Directory.GetFileSystemEntries(path, "*", SearchOption.AllDirectories))
{
    var output = Regex.Replace(f, @"^" + path, newPath);
    if (File.Exists(f)) File.Copy(f, output, true);
    else Directory.CreateDirectory(output);
}

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;
        }
    }

对于UWP和Winui 3 (WindowsAppSdk)使用Async API:

public async Task CopyAsync(StorageFolder source, StorageFolder dest)
{
    foreach (var item in await source.GetItemsAsync())

        if (item is StorageFile file)
            await file.CopyAsync(dest);

        else if (item is StorageFolder folder)
            await CopyAsync(folder, await dest.CreateFolderAsync(folder.Name, CreationCollisionOption.OpenIfExists));
}

你可以一直使用这个，摘自微软网站。

static void Main()
{
    // Copy from the current directory, include subdirectories.
    DirectoryCopy(".", @".\temp", true);
}

private static void DirectoryCopy(string sourceDirName, string destDirName, bool copySubDirs)
{
    // Get the subdirectories for the specified directory.
    DirectoryInfo dir = new DirectoryInfo(sourceDirName);

    if (!dir.Exists)
    {
        throw new DirectoryNotFoundException(
            "Source directory does not exist or could not be found: "
            + sourceDirName);
    }

    DirectoryInfo[] dirs = dir.GetDirectories();
    // If the destination directory doesn't exist, create it.
    if (!Directory.Exists(destDirName))
    {
        Directory.CreateDirectory(destDirName);
    }

    // Get the files in the directory and copy them to the new location.
    FileInfo[] files = dir.GetFiles();
    foreach (FileInfo file in files)
    {
        string temppath = Path.Combine(destDirName, file.Name);
        file.CopyTo(temppath, false);
    }

    // If copying subdirectories, copy them and their contents to new location.
    if (copySubDirs)
    {
        foreach (DirectoryInfo subdir in dirs)
        {
            string temppath = Path.Combine(destDirName, subdir.Name);
            DirectoryCopy(subdir.FullName, temppath, copySubDirs);
        }
    }
}

下面的代码是微软建议如何复制目录 由亲爱的@iato分享 但是它只是递归地复制源文件夹的子目录和文件，而不复制源文件夹本身(如右键单击->复制)。

但在这个答案下面有一个棘手的方法:

private static void DirectoryCopy(string sourceDirName, string destDirName, bool copySubDirs = true)
        {
            // Get the subdirectories for the specified directory.
            DirectoryInfo dir = new DirectoryInfo(sourceDirName);

            if (!dir.Exists)
            {
                throw new DirectoryNotFoundException(
                    "Source directory does not exist or could not be found: "
                    + sourceDirName);
            }

            DirectoryInfo[] dirs = dir.GetDirectories();
            // If the destination directory doesn't exist, create it.
            if (!Directory.Exists(destDirName))
            {
                Directory.CreateDirectory(destDirName);
            }

            // Get the files in the directory and copy them to the new location.
            FileInfo[] files = dir.GetFiles();
            foreach (FileInfo file in files)
            {
                string temppath = Path.Combine(destDirName, file.Name);
                file.CopyTo(temppath, false);
            }

            // If copying subdirectories, copy them and their contents to new location.
            if (copySubDirs)
            {
                foreach (DirectoryInfo subdir in dirs)
                {
                    string temppath = Path.Combine(destDirName, subdir.Name);
                    DirectoryCopy(subdir.FullName, temppath, copySubDirs);
                }
            }
        }

如果你想递归复制源文件夹和子文件夹的内容，你可以像这样简单地使用它:

string source = @"J:\source\";
string dest= @"J:\destination\";
DirectoryCopy(source, dest);

但是如果你想复制源目录自己(类似于你右键单击源文件夹，然后单击复制，然后在目标文件夹中单击粘贴)，你应该像这样使用:

 string source = @"J:\source\";
 string dest= @"J:\destination\";
 DirectoryCopy(source, Path.Combine(dest, new DirectoryInfo(source).Name));

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);