//獲取所有檔案
private static void GetFileList(DirectoryInfo dir, List<FileInfo> fileList)
        {
            fileList.AddRange(dir.GetFiles());
            foreach (DirectoryInfo directory in dir.GetDirectories()) GetFileList(directory, fileList);
        }
//獲取所有目錄
        private static void GetDirList(DirectoryInfo dir, List<DirectoryInfo> dirList)
        {
            dirList.AddRange(dir.GetDirectories());
            
 
foreach (DirectoryInfo directory in dir.GetDirectories()) GetDirList(directory, dirList);
        }

public static void CopyDireToDire(string sourceDire, string destDire, string backupsDire)
        {
            if (!Directory.Exists(destDire)) { Directory.CreateDirectory(destDire); }
            if
 
 (!Directory.Exists(backupsDire)) { Directory.CreateDirectory(backupsDire); }
            DirectoryInfo sourceDireInfo = new DirectoryInfo(sourceDire);
            List<FileInfo> fileList = new List<FileInfo>();
            GetFileList(sourceDireInfo, fileList);
            List<DirectoryInfo> dirList = new
 
 List<DirectoryInfo>();
            GetDirList(sourceDireInfo, dirList);          
//新增不存在目錄
foreach (DirectoryInfo dir in dirList)
            {
                string m = dir.FullName;
                string n = m.Replace(sourceDire, destDire);
                if (!Directory.Exists(n))
                {
                    Directory.CreateDirectory(n);
                }
                string o = m.Replace(sourceDire, backupsDire);
                if (!Directory.Exists(o))
                {
                    Directory.CreateDirectory(o);
                }
            }
//替換檔案，並備份
            foreach (FileInfo fileInfo in fileList)
            {
                string sourceFile = fileInfo.FullName;
                string destFile = sourceFile.Replace(sourceDire, destDire);

                if (File.Exists(destFile))
                {
                    string backFile = destFile.Replace(destDire, backupsDire);
                    File.Copy(destFile, backFile, true);
                }
                File.Copy(sourceFile, destFile, true);
            }
        }

部分參考其他的，