一个C#中接口模式的例子

BDataServices类中，LendRender应用一个委托BorrowReader实现对文件的读操作，LendRender2应用接口类实现文件读操作。

 1namespace datalayer
 2{
 3    public delegate object BorrowReader(string strPath);
 4    /**//// <summary>
 5    /// The class to provide data
 6    /// </summary>
 7    public class DataServices
 8    {
 9        public DataServices()
10        {
11            // 
12            // TODO: Add constructor logic here
13            //
14        }
15        public static object LendRender(string strFile,BorrowReader borrower)
16        {
17                
18            return borrower(strFile);
19        }
20        public static object LendRender2(string strFile,IBorrowReader borrower)
21        {
22                            
23            return borrower.borrowReader(strFile);
24        }
25    }
26    public interface IBorrowReader
27    {
28        object borrowReader(string strFile);
29    }
30}
31

调用类，定义一个BorrowReader对象br，为br增加相应的代理实体函数。

using System;
using System.Data;
using System.IO;
namespace DP_Interface
{
    /**//// <summary>
    /// Summary description for Class1.
    /// </summary>
    class Class1
    {
        /**//// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main(string[] args)
        {
            //
            // TODO: Add code to start application here
            //
            Console.WriteLine("----read by delegate");
            datalayer.BorrowReader br;
            br=new datalayer.BorrowReader(readTxt);
            br+=new datalayer.BorrowReader(readTxt);
            br+=new datalayer.BorrowReader(readTxt);
            datalayer.DataServices.LendRender("test.txt",br);
            Console.WriteLine("----read by interface");
            datalayer.DataServices.LendRender2("test.txt",new borrower());
            Console.Read();
            
        }
        public static object readTxt(string strPath)
        {
            StreamReader sr=new StreamReader(strPath,System.Text.Encoding.ASCII,false,8000);
            string strContent;
            while((strContent=sr.ReadLine())!=null)
            {
                Console.WriteLine(strContent);
            }            
            return null;
        }
    }
    class borrower:datalayer.IBorrowReader
    {
        public object borrowReader(string strFile)
        {
            StreamReader sr=new StreamReader(strFile,System.Text.Encoding.ASCII,false,8000);
            string strContent;
            while((strContent=sr.ReadLine())!=null)
            {
                Console.WriteLine(strContent);
            }
            
            return null;

        }
    }
}

文件test.txt内容为：
ste str
abcdef
输出结果为：
----read by delegate
ste str
abcdef
ste str
abcdef
ste str
abcdef
----read by interface
ste str
abcdef