C# 接口（Interface）

聲明接口

接口使用 interface 關鍵字聲明，它與類的聲明類似。接口聲明默認是 public 的。下面是一個接口聲明的實例：

public interface ITransactions
{
   // 接口成員
   void showTransaction();
   double getAmount();
}

實例

下面的實例演示了上面接口的實現：

using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace InterfaceApplication
{

   public interface ITransactions
   {
      // 接口成員
      void showTransaction();
      double getAmount();
   }
   public class Transaction : ITransactions
   {
      private string tCode;
      private string date;
      private double amount;
      public Transaction()
      {
         tCode = " ";
         date = " ";
         amount = 0.0;
      }
      public Transaction(string c, string d, double a)
      {
         tCode = c;
         date = d;
         amount = a;
      }
      public double getAmount()
      {
         return amount;
      }
      public void showTransaction()
      {
         Console.WriteLine("Transaction: {0}", tCode);
         Console.WriteLine("Date: {0}", date);
         Console.WriteLine("Amount: {0}", getAmount());

      }

   }
   class Tester
   {
      static void Main(string[] args)
      {
         Transaction t1 = new Transaction("001", "8/10/2012", 78900.00);
         Transaction t2 = new Transaction("002", "9/10/2012", 451900.00);
         t1.showTransaction();
         t2.showTransaction();
         Console.ReadKey();
      }
   }
}

當上面的代碼被編譯和執行時，它會產生下列結果：

Transaction: 001
Date: 8/10/2012
Amount: 78900
Transaction: 002
Date: 9/10/2012
Amount: 451900