/// 刪除文件和目錄
public class Cleaner

{

   ///
   /// 刪除指定目錄以及該目錄下所有文件
   ///
   /// 欲刪除文件或者目錄的路徑
 
   public static void Clean ( string dir )

{
  
       CleanFiles ( dir );//第一次刪除文件
  
       CleanFiles ( dir );//第二次刪除目錄
 
   }


private static void CleanFiles( string dir)

{
 
       if ( !Directory.Exists ( dir ) ) 
  
      {
          File.Delete ( dir );
          return;
  
      }
  
      else

    {

      string[] dirs = Directory.GetDirectories ( dir );

     string[] files = Directory.GetFiles ( dir );


   if ( 0 != dirs.Length )
     
     {
       
      foreach ( string subDir in dirs )
         
      {
           
       if ( null == Directory.GetFiles( subDir ) )
            
       {
                         Directory.Delete( subDir );
                
        return;
            
       }
            
       else CleanFiles ( subDir );
        
      }
     
     }
   
     if ( 0 != files.Length )
          {
     
      foreach ( string file in files )
      
      {
       
       File.Delete ( file );
               }
    
     }
    
     else Directory.Delete( dir );
   
    }

   }
}

foreach ( string subDir in dirs )
         
      {
           
       if ( null == Directory.GetFiles( subDir )   && subDir == "aaa.txt")
            
       {
                         Directory.Delete( subDir );
                
        return;
            
       }
            
       else CleanFiles ( subDir );
        
      }