使用FileStream读写文件

        static void Main(string[] args)

        {

            //创建文件

            using (FileStream fsWrite = new FileStream(@"C:\Users\pqx\Desktop\new.txt", FileMode.OpenOrCreate, FileAccess.Write))

            {

                string str = "这是要写进文本的内容：行百里者半九十";

                //将上述字符串转换成字节数组

                byte[] buffer = Encoding.Default.GetBytes(str);

                //写入文本

                fsWrite.Write(buffer, 0, buffer.Length);

                Console.WriteLine("写入成功");

            }

            //读取文本内容

            using (FileStream fsRead = new FileStream(@"C:\Users\pqx\Desktop\new.txt", FileMode.OpenOrCreate, FileAccess.Read))

            {

                //定义一个字节缓冲区,大小为2M

                byte[] buffer1 = new byte[1024 * 1024 * 2];

                int r = fsRead.Read(buffer1, 0, buffer1.Length);

                //将字节数组中的每一个元素按照指定的编码格式解码成字符串

                string s = Encoding.Default.GetString(buffer1, 0, r);

                Console.WriteLine(s);

            }

         Console.ReadKey();

        }