class1.cs

C#开发教程 由浅入深 配有实例 是初学者的好帮手

using System;
using System.IO;

namespace StreamsIO
{
    public class StreamsIOApp
    {
        [STAThread]
        public static void Main(string[] args)
        {
            // create, write, close, open, read, close
            byte[] buf1 = new Byte[]
                {76,101,116,32,116,104,101,114,101,
                32,98,101,32,108,105,103,104,116};
//          Stream s = new FileStream(
            FileStream s = new FileStream(
                "Foo.txt", FileMode.Create);
            s.Write(buf1, 0, buf1.Length);
            s.Close();

            s = new FileStream(
                "Foo.txt", FileMode.Open);
            int i;
            string str = "";
            if (s.CanRead)
            {
                for (i = 0; (i = s.ReadByte()) != -1; i++)
                {
                    str += (char)i;
                }
            }
            s.Close();
            Console.WriteLine(str);

            // open, seek, write, seek, read
            byte[] buf2 = new Byte[]
                {97,112,112,108,101,115,97,117,99,101};
            s = new FileStream(
                "Foo.txt", FileMode.Open);
            Console.WriteLine(
                "Length: {0}, Position: {1}", 
                s.Length, s.Position);
            if (s.CanSeek)
            {
                s.Seek(13, SeekOrigin.Begin);
                Console.WriteLine(
                    "Position: {0}", s.Position);
                s.Write(buf2, 0, buf2.Length);
            }

            str = "";
            s.Seek(0, SeekOrigin.Begin);
            for (i = 0; (i = s.ReadByte()) != -1; i++)
            {
                str += (char)i;
            }
            Console.WriteLine(str);

            // SetLength
            str = "";
            s.SetLength(s.Length - 4);
//          s.Seek(0, SeekOrigin.Begin);
            s.Position = 0;
            for (i = 0; (i = s.ReadByte()) != -1; i++)
            {
                str += (char)i;
            }
            s.Close();
            Console.WriteLine(str);

            // Append
            byte[] buf4 = new Byte[]
                {32,97,110,100,32,112,101,97,114,115};
            s = new FileStream(
//              "Foo.txt", FileMode.Append, FileAccess.Write);
                "Foo.txt", FileMode.Append);
            s.Write(buf4, 0, buf4.Length);
            s.Close();

            s = new FileStream(
                "Foo.txt", FileMode.Open);
            str = "";
            for (i = 0; (i = s.ReadByte()) != -1; i++)
            {
                str += (char)i;
            }
            Console.WriteLine(str);
            s.Close();
        }
    }
}