using System;

namespace ConsoleApplication1
{
    /// <summary>
    /// Class1 的摘要说明。
    /// </summary>
    class Class1
    {
        /// <summary>
        /// 应用程序的主入口点。
        /// </summary>
        /// 
        //定义个新委托
        delegate int Dec(int a,int b);

        [STAThread]
        static void Main(string[] args)
        {
            //实例化一个委托
            Dec dec = new Dec(DeleDec);
            //调用该委托
            Console.Write(dec(50,20));
        }
        
        private static int DeleDec(int i,int j)
        {
            return (i - j);
        }

    }
}

public delegate void ProcessBookDelegate(Book book);

public void ProcessPaperbackBooks(ProcessBookDelegate processBook)
      {
         foreach (Book b in list) 
         {
            if (b.Paperback)
            // Calling the delegate:
               processBook(b);
         }
      }


// Create a new delegate object associated with the static 
// method Test.PrintTitle:
bookDB.ProcessPaperbackBooks(new ProcessBookDelegate(PrintTitle));

PriceTotaller totaller = new PriceTotaller();

// Create a new delegate object associated with the nonstatic 
// method AddBookToTotal on the object totaller:
bookDB.ProcessPaperbackBooks(new ProcessBookDelegate(totaller.AddBookToTotal));