C#中I/O操作

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

using System.IO;

namespace TextFile
{
    public partial class FrmFile : Form
    {
        int Count = 0;
        public FrmFile()
        {
            InitializeComponent();
        }

        //写入文件
        private void btnWrite_Click(object sender, EventArgs e)
        {
            //【1】创建文件流
            FileStream fs = new FileStream("F:\\myfile.txt",FileMode.Create);
            //【2】创建写入器
            StreamWriter sw = new StreamWriter(fs);
            //【3】以流的方式写入数据
            sw.Write(this.txtFile.Text.Trim());
            //【4】关闭写入器
            sw.Close();
            //【5】关闭文件流
            fs.Close();
        }

        //读取文件
        private void btnRead_Click(object sender, EventArgs e)
        {
            //【1】创建文件流
            FileStream fs = new FileStream("F:\\myfile.txt",FileMode.Open);
            //【2】创建读取器
            // StreamReader sr = new StreamReader(fs,Encoding.Default);   //encoding,default 读取默认的编码方法
            StreamReader sr = new StreamReader(fs);
            //【3】以流的方式读取数据
            this.txtFile.Text=sr.ReadToEnd();
            //【4】关闭读取器
            sr.Close();
            //【5】关闭文件流
            fs.Close();
        }

        //模拟写日志
        private void button1_Click(object sender, EventArgs e)
        {
            Count++;

            //创建文件流
            FileStream fs = new FileStream("F:\\myfile.txt",FileMode.Append);
            //创建写入器
            StreamWriter sr = new StreamWriter(fs);
            //以流的方式逐行写入数据
            sr.WriteLine(DateTime.Now.ToString()+"：次数" + "{0}",Count);
            //关闭写入器
            sr.Close();
            //关闭文件流
            fs.Close();

        }

        //删除文件
        private void btnDelete_Click(object sender, EventArgs e)
        {
            File.Delete(this.txtThisFile.Text.Trim());
        }

        //复制文件
        private void btnCopy_Click(object sender, EventArgs e)
        {
            //若目标文件已经存在,则删除该文件
            if(File.Exists(this.txtOtherFile.Text.Trim()))
            {
                File.Delete(this.txtOtherFile.Text.Trim());
            }
            else
            {
                //判断源文件是否存在
                if (!File.Exists(this.txtThisFile.Text.Trim()))
                {
                    MessageBox.Show("不存在源文件", "错误提示",MessageBoxButtons.OK,MessageBoxIcon.Warning);
                }
                else
                {
                    File.Copy(this.txtThisFile.Text.Trim(), this.txtOtherFile.Text.Trim());
                }
              
            }
        }

        //移动文件
        private void btnMove_Click(object sender, EventArgs e)
        {
            //若目标文件已经存在,则删除该文件
            if (File.Exists(this.txtOtherFile.Text.Trim()))
            {
                File.Delete(this.txtOtherFile.Text.Trim());
            }
            else
            {
                //判断源文件是否存在
                if (!File.Exists(this.txtThisFile.Text.Trim()))
                {
                    MessageBox.Show("不存在源文件,移动失败！", "错误提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                }
                else
                {
                    File.Move(this.txtThisFile.Text.Trim(), this.txtOtherFile.Text.Trim());
                }

            }
        }
        //显示指定目录下的所有文件
        private void btnShowAllFile_Click(object sender, EventArgs e)
        {
            string[] files = Directory.GetFiles("F:\\图书");
            this.txtFile.Clear();
            foreach (string item in files)
            {
                this.txtFile.Text+=item+"\r\n";
            }
        }

        //显示指定目录下的文件
        private void btnShowOneFile_Click(object sender, EventArgs e)
        {
            string[] dirs = Directory.GetDirectories("F:\\图书");
            this.txtFile.Clear();
            foreach (string item in dirs)
            {
                this.txtFile.Text += item + "\r\n";
            }
        }

        //在指定目录下创建一个子目录
        private void btnNewOneFile_Click(object sender, EventArgs e)
        {
            Directory.CreateDirectory("F:\\图书\\包子林");
        }

        //删除指定目录下的所有目录和文件
        private void btnDeleteAllFile_Click(object sender, EventArgs e)
        {
            //Directory.Delete("F:\\图书\\包子林");  //删除包子林文件夹时出错--使用该方法，目录必须为空
            DirectoryInfo dir = new DirectoryInfo("F:\\图书\\包子林");
            dir.Delete(true);
        }
    }
}