C#------封装文件拷贝方法

 class Program
    {
        static void Main(string[] args)
        {
            //FileStream 拷贝方法封装
            using(Stream fs = new FileStream(@"C:\Users\Administrator\Desktop\C#OOP练习\du.txt",FileMode.Open))
            using(Stream fs1 = new FileStream(@"C:\Users\Administrator\Desktop\C#OOP练习\xie.txt",FileMode.Create))
            {
                Copy(fs, fs1, 4);
            }
            Console.WriteLine("拷贝完成");

        }

        static void Copy(Stream Du, Stream Xie, int size)//文件读，文件写，读取多少
        {
            byte[] bytes = new byte[size];
            int len = 0;
            while ((len = Du.Read(bytes, 0, bytes.Length)) > 0)
            {
                Xie.Write(bytes, 0, len);
            }
        }
    }