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);
            }
    }

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);
}

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);
            }
    }

递归复制文件夹而不递归，以避免堆栈溢出。

public static void CopyDirectory(string source, string target)
{
    var stack = new Stack<Folders>();
    stack.Push(new Folders(source, target));

    while (stack.Count > 0)
    {
        var folders = stack.Pop();
        Directory.CreateDirectory(folders.Target);
        foreach (var file in Directory.GetFiles(folders.Source, "*.*"))
        {
            File.Copy(file, Path.Combine(folders.Target, Path.GetFileName(file)));
        }

        foreach (var folder in Directory.GetDirectories(folders.Source))
        {
            stack.Push(new Folders(folder, Path.Combine(folders.Target, Path.GetFileName(folder))));
        }
    }
}

public class Folders
{
    public string Source { get; private set; }
    public string Target { get; private set; }

    public Folders(string source, string target)
    {
        Source = source;
        Target = target;
    }
}

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);
        }
    }
}

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.
}