共实这是一个递归调用的问题.很简单,代码如下:

public   void   CopyDirectory(   string   sourceDirName,   string   destDirName)  
        {
            try
            {
                if (!Directory.Exists(destDirName))
                {
                    Directory.CreateDirectory(destDirName);
                    File.SetAttributes(destDirName, File.GetAttributes(sourceDirName));

                }

                if (destDirName[destDirName.Length - 1] != Path.DirectorySeparatorChar)
                    destDirName = destDirName + Path.DirectorySeparatorChar;

                string[] files = Directory.GetFiles(sourceDirName);
                foreach (string file in files)
                {                     
                    if(File.Exists(destDirName + Path.GetFileName(file)))
                        continue;
                    File.Copy(file, destDirName + Path.GetFileName(file),true);
                    File.SetAttributes(destDirName + Path.GetFileName(file), FileAttributes.Normal);
                    total++;
                }

                string[] dirs = Directory.GetDirectories(sourceDirName);
                foreach (string dir in dirs)
                {
                    CopyDirectory(dir, destDirName + Path.GetFileName(dir));
                }
            }
            catch (Exception ex)
            {
                StreamWriter sw = new StreamWriter(Application.StartupPath+"\\log.txt",true);
                sw.Write(ex.Message+"     "+DateTime.Now+"\r\n");
                sw.Close();
            }
        }