【C#】201801013关于文件的操作

1、基于流的文本文件的读写对于C#来说比较简单，通常来讲，需要以下5个基本步骤：

1. 创建一个文件流——FileStream
2. 创建读取器或写入器——StreamReader/StreamWriter
3. 执行读或者写操作
4. 关闭读取器或写入器
5. 关闭文件流

2、BinaryReader和BinaryWriter类可用于读写二进制文件
这两个类并不派生于Stream，而是直接派生于System.Object类
所有创建两个类的对象必须基于所提供的派生于Stream类的对象，如FileStream类的对象

3、File类和FileInfo类——文件基本操作
Directory类和DirectoryInfo类——目录基本操作
Path类和Enviroment类——路径类和系统信息类

4、当要读取的文件中包含汉字，需要指定编码Encoding.GetEncoding(“GB2312”)
string[ ] content=File.ReadAllLines(path，Encoding.GetEncoding(“GB2312”))；

5、读写文本文件

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

namespace WindowsFormsApp4
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void btnRead_Click(object sender, EventArgs e)
        {
            if (ofdOpen.ShowDialog() == DialogResult.OK)
            {
                string filePath = ofdOpen.FileName;
                txtFilePath.Text = filePath;

                if (File.Exists(filePath))
                {
                    StreamReader sr = new StreamReader(filePath, Encoding.GetEncoding("gb2312"));
                    string input;
                    while ((input = sr.ReadLine()) != null)
                    {
                        txtFileContent.Text += input + "\r\n";
                    }
                    sr.Close();
                }
                else
                {
                    MessageBox.Show("您要读取的文件不存在！");
                }
            }
        }

        private void btnWrite_Click(object sender, EventArgs e)
        {
            sfdSave.Filter = "文本文件(*.txt)|*.txt";
            if (sfdSave.ShowDialog() == DialogResult.OK)
            {
                string filePath = sfdSave.FileName;
                StreamWriter sw = new StreamWriter(filePath, false);
                sw.WriteLine(txtFileContent.Text);
                sw.Close();
            }
        }
    }
}

6、文件基本操作

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
using Microsoft.VisualBasic.Devices;

namespace WindowsFormsApp3
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void label1_Click(object sender, EventArgs e)
        {

        }

        private void btnCreate_Click(object sender, EventArgs e)
        {
            string path = @txtFile.Text;
            if (File.Exists(path))
                MessageBox.Show("文件名已存在");
            try
            {
                using(StreamWriter sw = File.CreateText(path))
                {
                    sw.WriteLine("不想说话");
                    sw.WriteLine("");
                    sw.WriteLine("建立日期时间"+DateTime.Now.ToString());
                    sw.Flush();
                    MessageBox.Show("文件创建成功！");
                }
            }
            catch(Exception ex)
            {
                MessageBox.Show("文件无法建立。" + Environment.NewLine + "请确认文件名称是否正确," + "以及您是否拥有建立权限。");
            }
        }

        private void btnCopy_Click(object sender, EventArgs e)
        {
            try
            {
                File.Copy(@"d:\t87.txt", @"d:\t87_1.txt", true);
                FileInfo fi = new FileInfo(@"d:\t87.txt");
                fi.CopyTo(@"d:\t87_2.txt", true);
                MessageBox.Show("文件已复制");
            }
            catch(Exception ex)
            {
                MessageBox.Show(ex.Message);
                return;
            }
        }

        private void btnRename_Click(object sender, EventArgs e)
        {
            try
            {
                Computer MyComputer = new Computer();
               // File.Copy(@"d:\t87.text", @"d:\t87_3.text", true);
                MyComputer.FileSystem.RenameFile(@"d:\t87.txt", "更改文件名.txt");
                MessageBox.Show("更改文件名成功！");
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
                return;
            }
        }

        private void btnMove_Click(object sender, EventArgs e)
        {
           if(File.Exists(@"d:\t87.txt")){

                //文件被线程占用，不能移动，解决方法可以重新Copy一个移动
                File.Copy(@"d:\t87.txt", @"d:\移动.txt",true);
                File.Move(@"d:\移动.txt", @"d:\移动1.txt");
                MessageBox.Show("文件移动成功！");
            }
            else
            {
                FileInfo fi = new FileInfo(@"d:\t87.txt");
                StreamWriter sw = fi.CreateText();
                MessageBox.Show("移动前实例化文件" + fi.Name);

                //文件被线程占用，不能移动
                fi.CopyTo(@"d:\移动2.txt");
                
            }
           
        }

        private void btnDelete_Click(object sender, EventArgs e)
        {
            try
            {
                if (File.Exists(@"d:\t87.txt"))
                    File.Delete(@"d:\t87.txt");
                else
                {
                    FileInfo fi = new FileInfo(@"d:\t87.txt");
                    StreamWriter sw = fi.CreateText();
                    MessageBox.Show("删除前实例化文件" + fi.Name);
                }

                MessageBox.Show("文件删除成功！");
            }
            catch(Exception ex)
            {
                MessageBox.Show(ex.Message);
                return;
            }
        }
    }
}