C#之文件的读写（一）

整个系统的界面如下：

先上代码：

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;

namespace WindowsFormsApp1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        private static string directory_path = @"E:studycodeC#winform2017-12-9WindowsFormsApp11";
        private static string directory_otherpath = @"E:studycodeC#winform2017-12-9";
        private static string directory_anotherpath = "E:\study\code\C#\winform\2017-12-9\WindowsFormsApp1\";
        //private static string directory_vv = "E:\study\code\C#\winform\2017-12-9\WindowsFormsApp1\12.txt";
        private void groupBox1_Enter(object sender, EventArgs e)
        {

        }
        /// <summary>
        /// 创建目录
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                Directory.CreateDirectory(directory_path);
                button1.Enabled = false;
                button2.Enabled = true;
                button3.Enabled = true;
                button1.Enabled = true;
                MessageBox.Show("文件夹成功建立","提示！");
            }
            catch (Exception mm)
            {
                MessageBox.Show("磁盘操作错误，原因：" + Convert.ToString(mm), "提示！");
            }
        }
        /// <summary>
        /// 删除目录
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button2_Click(object sender, EventArgs e)
        {
            try
            {
                Directory.Delete(directory_path);
                button2.Enabled = false;
                button1.Enabled = true;
                button3.Enabled = false;
                button4.Enabled = false;
                MessageBox.Show("文件夹删除成功","提示！");
            }
            catch (Exception mm)
            {
                MessageBox.Show("磁盘操作错误，原因：" + Convert.ToString(mm), "提示！");               
            }
        }
        /// <summary>
        /// 移动目录
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button3_Click(object sender, EventArgs e)
        {
            try
            {
                Directory.Move(directory_path, directory_otherpath);
                MessageBox.Show("文件夹移动成功", "提示！");
            }
            catch (Exception mm)
            {
                MessageBox.Show("磁盘操作错误，原因：" + Convert.ToString(mm), "提示！");
                
            }
        }
        /// <summary>
        /// 目录创建时间
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button4_Click(object sender, EventArgs e)
        {
            try
            {
                MessageBox.Show(string.Format("{0:G}",Directory.GetCreationTime(directory_path)),"提示！");
            }
            catch (Exception mm)
            {
                MessageBox.Show("磁盘操作错误，原因：" + Convert.ToString(mm), "提示！");
            }
        }

        /// <summary>
        /// 创建文本文件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button5_Click(object sender, EventArgs e)
        {

            try
            {
                if (textBox1.Text.Length == 0)
                    MessageBox.Show("文件名禁止为空", "提示！");
                else
                {
                    directory_anotherpath = directory_anotherpath + textBox1.Text.Trim() + ".txt";
                    StreamWriter sw = File.CreateText(directory_anotherpath);
                    richTextBox1.Enabled = true;
                    MessageBox.Show("文件创建成功。", "提示！");
                    sw.Close();
                }
            }
            catch (Exception mm)
            {
                MessageBox.Show("磁盘操作错误，原因：" + Convert.ToString(mm), "提示！");
            }
        }
        /// <summary>
        /// 打开文本文件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button7_Click(object sender, EventArgs e)
        {
            try
            {
                OpenFileDialog open = new OpenFileDialog();
                open.Title = "打开文本文件";
                open.FileName = "";
                open.AddExtension = true;
                open.CheckFileExists = true;
                open.CheckPathExists = true;
                open.Filter = "文本文件(*.txt) | *.txt";
                open.ValidateNames = true;
                if (open.ShowDialog() == DialogResult.OK)
                {
                    StreamReader sr = new StreamReader(open.FileName,System.Text.Encoding.Default);
                    this.richTextBox1.Text = sr.ReadToEnd();
                    MessageBox.Show("文件打开成功","提示！");
                    richTextBox1.Enabled = true;
                    sr.Close();
                }
                
                
            }
            catch (Exception mm)
            {
                MessageBox.Show("磁盘操作错误，原因：" + Convert.ToString(mm), "提示！");
            }
        }

        /// <summary>
        /// 保存编辑文件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button6_Click(object sender, EventArgs e)
        {
            try
            {
                FileStream textfile = File.Open(directory_anotherpath, FileMode.OpenOrCreate, FileAccess.Write);
                StreamWriter sw = new StreamWriter(textfile, Encoding.GetEncoding("GB2312"));
                sw.WriteLine(richTextBox1.Text.ToString());
                MessageBox.Show("文件写成功","提示！");
                sw.Close();
            }
            catch (Exception mm)
            {
                MessageBox.Show("磁盘操作错误，原因：" + Convert.ToString(mm), "提示！");
            }
        }
    }
}

---

分析：

分析代码进行窗口调试调整的时候，用try catch finally 组合会使得整个程序不会出现致命性异常。

 

创建目录：

 

使用directory类的创建目录方法的功能。

directory_path 是自己设定的文件路径，注意有@和没@得区别。

删除目录和移动目录应用的同样是Directory类中的方法。

目录创建时间：

MessageBox.Show(string.Format("{0:G}",Directory.GetCreationTime(directory_path)),"提示！");

Format是String类中的一个格式化数据的一个方法。

创建文本文件：

CreateText(string FilePath) 方法是创建或打开一个文件，用于写入UTF-8 编码的文件

File.CreateText 返回的一个StreamWriter对象。使用完要关闭。

 sw.Close();

打开文本文件：

OpenFileDialog 是创建一个打开的对话框

其中要设置对话框的属性：

基本属性设置。

    StreamReader sr = new StreamReader(open.FileName,System.Text.Encoding.Default);
    this.richTextBox1.Text = sr.ReadToEnd();

fileName是选择后的文件打开路径，Encoding.Default是获取操作系统当前ANSI代码页的编码。(ANSI代码是一种字符代码)

打开读取成功后要记得关闭StreamReader的对象。

保存编辑文件：

  FileStream textfile = File.Open(directory_anotherpath,  FileMode.OpenOrCreate, FileAccess.Write);

设置读写模式和访问权限的流。

定义读的流对象，并将FileStream对象写入StreamReader对象中，并设置格式。

保存成功后要关闭。