文件流，文件流的练习.

    class Program
    {
        static void Main(string[] args)
        {
            //使用FileStream来读取数据
            FileStream fsRead = new FileStream(@"C:\Users\SpringRain\Desktop\new.txt", FileMode.OpenOrCreate, FileAccess.Read);
            byte[] buffer = new byte[1024 * 1024 * 5];
            //3.8M  5M
            //返回本次实际读取到的有效字节数
            int r = fsRead.Read(buffer, 0, buffer.Length);
            //将字节数组中每一个元素按照指定的编码格式解码成字符串
            string s = Encoding.UTF8.GetString(buffer, 0, r);
            //关闭流
            fsRead.Close();
            //释放流所占用的资源
            fsRead.Dispose();
            Console.WriteLine(s);
            Console.ReadKey();



            //使用FileStream来写入数据
            //using (FileStream fsWrite = new FileStream(@"C:\Users\SpringRain\Desktop\new.txt", FileMode.OpenOrCreate, FileAccess.Write))
            //{
            //    string str = "看我游牧又把你覆盖掉";
            //    byte[] buffer = Encoding.UTF8.GetBytes(str);
            //    fsWrite.Write(buffer, 0, buffer.Length);
            //}
            //Console.WriteLine("写入OK");
            //Console.ReadKey();
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            //思路：就是先将要复制的多媒体文件读取出来，然后再写入到你指定的位置
            string source = @"C:\Users\SpringRain\Desktop\1、复习.wmv";
            string target = @"C:\Users\SpringRain\Desktop\new.wmv";
            CopyFile(source, target);
            Console.WriteLine("复制成功");
            Console.ReadKey();
        }

        public static void CopyFile(string soucre, string target)
        {
            //1、我们创建一个负责读取的流
            using (FileStream fsRead = new FileStream(soucre, FileMode.Open, FileAccess.Read))
            {
                //2、创建一个负责写入的流
                using (FileStream fsWrite = new FileStream(target, FileMode.OpenOrCreate, FileAccess.Write))
                {
                    byte[] buffer = new byte[1024 * 1024 * 5];
                    //因为文件可能会比较大，所以我们在读取的时候 应该通过一个循环去读取
                    while (true)
                    {
                        //返回本次读取实际读取到的字节数
                        int r = fsRead.Read(buffer, 0, buffer.Length);
                        //如果返回一个0，也就意味什么都没有读取到，读取完了
                        if (r == 0)
                        {
                            break;
                        }
                        fsWrite.Write(buffer, 0, r);
                    }              
                }
            }
        }


    }