string r =Convert.ToString(readline[color=#FF0000]()[/color]);

------解决方案--------------------
  string r =Convert.ToString(readline());

------解决方案--------------------
delegate string readscreen();
       static void Main(string[] args)
       {
           readscreen readline;
           readline = new readscreen(read);
           string r = Convert.ToString(readline());            Console.WriteLine("Your words are {0}", r);
           Console.Read();
       }
       static string read()
       {
           string line = Console.ReadLine();
           return line;
       }

------解决方案--------------------
根据你的意义，应该没有问题：

delegate string ReadEventHandler();

 static void Main(string[] args)
 {
    ReadEventHandler readline=new ReadEventHandler();
    Console.WriteLine(readline);
 }

 static string Read()
 {
    string line = Console.ReadLine();
    return line;
 }

以上代码返回：工程名称.Programe+ReadEventHandler;

------解决方案--------------------
  
上面纠正下：ReadEventHandler readline=new ReadEventHandler(Read);

或者如下写：
static void Main(string[] args)
{
  ReadEventHandler readline=delegate()
  {
   string line = Console.ReadLine();
    return line;
  };
}
OR
static void Main(string[] args)
{
  ReadEventHandler readline=new ReadEventHandler(()=>
  {
   string line = Console.ReadLine();
    return line;
  });
}

------解决方案--------------------
delegate string readscreen ();

这个委托的使用方法，
readscreen read=new readscreen(target);

调用方法： read();或read.invoke();



------解决方案--------------------


C# code

        /// <summary>
        /// 保存缓存
        /// </summary>
        /// <param name="key">键</param>
        /// <param name="value">值</param>
        public void SaveCache(object key, object value)
        {
            SaveCacheHandler handler = new SaveCacheHandler(SaveCacheInvoke);
            IAsyncResult ar = handler.BeginInvoke(key, value, new AsyncCallback(SaveCacheCallBack), null);
        }

        private void SaveCacheInvoke(object key, object value)
        {
            lock (hashtable.SyncRoot)
            {
                hashtable[key] = value;
            }
        }

        private void SaveCacheCallBack(IAsyncResult ar)
        {
            SaveCacheHandler handler = (SaveCacheHandler)((AsyncResult)ar).AsyncDelegate;
            handler.EndInvoke(ar);
        }