C#开发技术——实验08文件操作编程

【实验目的】

1．理解文件和流概念。

2．熟悉文件操作的方法。

3．掌握Fileatream类使用方法。

4．掌握StreamReader和StreamWriter使用方法。

5．掌握BinaryReader和BinaryWriter使用方法。

【实验内容】

以下5道实验题目最终效果，大家可运行“可执行文件”目录中各题。

1．分别利用File类和FileInfo类、Directory类和DirectoryInfo类实现文件和目录的创建、删除、复制、移动等操作。

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

namespace shiyan8
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            this.Text = "文件和目录操作实验";
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            this.label1.Text = "分别利用File类和FileInfo类、Directory类和DirectoryInfo类实现文件和目录的创建、删除、复制、移动等操作";
            this.label1.ForeColor = Color.Green;
            this.button1.Text = "File类操作";
            this.button2.Text = "FileInfo类操作";
            this.button3.Text = "Directory类操作";
            this.button4.Text = "DirectoryInfo类操作";
            this.button5.Text = "结束";
        }

        private void button1_Click(object sender, EventArgs e)
        {
            StreamWriter sw = File.CreateText("c:\\abc.txt");
            StreamReader sr = File.OpenText("c:\\abc.txt");
            bool isFileExist = File.Exists("c:\\abc.txt");
            File.Copy("c:\\abc.txt", "d:\\abc.txt", true);
            File.Move("c:\\abc.txt", "d:\\abc.txt");
            if (File.Exists("c:\\abc.txt"))
            {
                File.Delete("C:\\abc.txt");
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            FileInfo f = new FileInfo("c:\\abc.txt");
            if (!f.Exists)
            {
                f.CreateText();
            }
            StreamWriter sw = f.AppendText();
            sw.Write("增加一行数据");
            sw.Dispose();
            if (f.Exists)
            {
                f.CopyTo("d:\\abc.txt", true);
            }
            if (f.Exists)
            {
                f.Delete();
            }
            string name = f.Name;
            long len = f.Length;
            string text = f.Extension;
        }

        private void button3_Click(object sender, EventArgs e)
        {
            Directory.CreateDirectory("MyFolder1");
            Directory.CreateDirectory("C:\\MyFolder2");
            Directory.Move(@"E:\MyFolder", @"E:\Downloads\MyFolder");
            //Directory.Move(@"E:\MyFolder", @"C:\MyFolder");
            if (Directory.Exists(@"e:\MyFolder"))
            {
                Directory.Delete(@"e:\MyFolder");
            }
            DirectoryInfo myInfo = Directory.GetParent("e:\\download\\MyFolder");
            string strParentinfo = myInfo.FullName;
        }

        private void button4_Click(object sender, EventArgs e)
        {
            DirectoryInfo myinfo = new DirectoryInfo("C:\\muFolder");
            myinfo.Create();
            string strmyFolderFullName = myinfo.FullName;
            if (myinfo.Exists)
            {
                myinfo.Delete();
            }
        }

        private void button5_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }
    }
}

2．FileStream表示文件流，它能够打开和关闭文件，并对文件进行单字节的读写操作。如图8-1所示，使用FileStream实现文件读写操作。

要求：文件的读操作之前，要进行判断文件是否存在。程序界面如图实验8-1所示效果。

 

图8-1

using System;
using System.IO;
using System.Text;
using System.Windows.Forms;

namespace shiyan8
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
            this.Text = "FileStream类";
        }

        private void Form2_Load(object sender, EventArgs e)
        {
            this.label1.Text = "输入文件名（含盘符路径）：";
            this.label2.Text = "文件内容如下:";
            this.button1.Text = "读文件";
            this.button2.Text = "写文件";
            this.button3.Text = "结束";
        }

        private void button1_Click(object sender, EventArgs e)
        {
            FileStream fs = new FileStream(this.textBox1.Text, FileMode.Open, FileAccess.Read);
            long i = fs.Length;
            byte[] b = new byte[fs.Length];
            fs.Read(b, 0, b.Length);
            fs.Dispose();
            UTF8Encoding tmp = new UTF8Encoding();
            this.textBox2.Text = tmp.GetString(b);
        }

        private void button2_Click(object sender, EventArgs e)
        {
            string str = this.textBox1.Text;
            FileStream fs = new FileStream(str, FileMode.Append, FileAccess.Write);
            UTF8Encoding tmp = new UTF8Encoding();
            byte[] b = tmp.GetBytes(this.textBox2.Text);
            fs.Write(b, 0, b.Length);
            fs.Dispose();
        }

        private void button3_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }
    }
}

3．StreamWrite类可以实现文本文件写操作。设计一个如图8-2所示的窗体。窗体上有两个命令按钮、一个文本框。

具体要求：第一次单击“保存”按钮时，弹出一个保存对话框，并将内容利用StreamWrite类保存到指定文件中；以后再单击“保存”按钮，自动将最新内容保存下来，不再弹出对话框。

 

 

using System;
using System.IO;
using System.Windows.Forms;

namespace shiyan8
{
    public partial class Form3 : Form
    {
        public Form3()
        {
            InitializeComponent();
            this.Text = "StreamWrite类";
        }

        private void Form3_Load(object sender, EventArgs e)
        {
            this.button1.Text = "保存";
            this.button2.Text = "结束";
        }

        private void button1_Click(object sender, EventArgs e)
        {
            SaveFileDialog saveFileDialog1 = new SaveFileDialog();
            saveFileDialog1.InitialDirectory = "d:\\";
            saveFileDialog1.Filter = "*.txt|*.txt";
            saveFileDialog1.FilterIndex = 1;
            saveFileDialog1.RestoreDirectory = true;
            DialogResult dr = saveFileDialog1.ShowDialog();
            if (dr == DialogResult.OK && saveFileDialog1.FileName.Length > 0)
            {
                FileStream fs1 = new FileStream(saveFileDialog1.FileName, FileMode.Create);
                StreamWriter sw = new StreamWriter(fs1);
                sw.Write(textBox1.Text);
                sw.Close();
                fs1.Close();
            }
            DialogResult btn1 = MessageBox.Show("保存文件成功", "", MessageBoxButtons.OK);
        }

        private void button2_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }
    }
}

4．复制图片。创建一个如图实验8-3所示的窗体，窗体上放置两个按钮（button1、button2）、一个标签（label1，用于显示所选图片路径和文件名）、一个图片框（pictureBox1，用于显示所选图片）、一个打开对话框（penFileDialog1）、一个保存对话框（saveFileDialog1）。

实现功能：

（1）程序运行时，用户单击“选择图片”按钮，即可打开一个“打开对话框”，在该对话框中，文件类型可以是*.jpg或*.gif ；

（2）用户选取某个图片后，该图片显示在pictureBox1中，显示方式为缩放图片适应pictureBox1。此外，该图片文件路径及完整文件名在标签label1中显示出来。

（3）用户单击“复制图片”按钮，即可打开一个“保存对话框”。在该对话框中，文件扩展名类型可以是*.jpg或*.gif；用户在该对话框中输入保存后文件名即可实现复制图片框pictureBox1中的图片。

 

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

namespace shiyan8
{
    public partial class Form4 : Form
    {
        public Form4()
        {
            InitializeComponent();
            this.Text = "复制图片";
        }

        private void Form4_Load(object sender, EventArgs e)
        {
            this.button1.Text = "选择图片";
            this.button2.Text = "复制图片";
        }

        private void button1_Click(object sender, EventArgs e)
        {
            OpenFileDialog saveFileDialog1 = new OpenFileDialog();
            saveFileDialog1.InitialDirectory = "d:\\";
            saveFileDialog1.Filter = "*.jpg|*.jpg|*.gif|*.gif";
            saveFileDialog1.FilterIndex = 1;
            saveFileDialog1.RestoreDirectory = true;
            DialogResult dr = saveFileDialog1.ShowDialog();
            if (dr == DialogResult.OK && saveFileDialog1.FileName.Length > 0)
            {
                string strpath = saveFileDialog1.FileName;
                this.label1.Text = strpath;
                FileStream fs = new FileStream(strpath, FileMode.Open);
                byte[] by = new byte[fs.Length];
                BinaryReader br = new BinaryReader(fs);
                by = br.ReadBytes(Convert.ToInt32(fs.Length));
                MemoryStream ms = new MemoryStream(by);
                Bitmap btm = new Bitmap(ms);
                pictureBox1.Image = btm;
                br.Close();
                ms.Close();
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            SaveFileDialog saveFileDialog1 = new SaveFileDialog();
            saveFileDialog1.InitialDirectory = "d:\\";
            saveFileDialog1.Filter = "*.jpg|*.jpg|*.gif|*.gif";
            saveFileDialog1.FilterIndex = 1;
            saveFileDialog1.RestoreDirectory = true;
            DialogResult dr = saveFileDialog1.ShowDialog();
            if (dr == DialogResult.OK && saveFileDialog1.FileName.Length > 0)
            {
                string str = saveFileDialog1.FileName;
                FileStream ip = new FileStream(this.label1.Text, FileMode.Open, FileAccess.Read);
                FileStream op = new FileStream(str, FileMode.OpenOrCreate, FileAccess.Write);
                int buffer = Convert.ToInt32(ip.Length);
                int bytes;
                byte[] by = new byte[buffer];
                BinaryReader br = new BinaryReader(ip);
                BinaryWriter bw = new BinaryWriter(op);
                while ((bytes = br.Read(by, 0, buffer))>0)
                {
                    bw.Write(by, 0, bytes);
                }
                br.Close();
                bw.Close();
                ip.Close();
                op.Close();
            }
        }
    }
}

5．递归挂树。创建一个如图实验8-4所示的窗体，窗体上放置一个按钮（名称为button1，文本为“递归挂树”）、TreeView控件（treeView1）。单击“递归挂树”按钮，实现效果如图8-4所示。递归挂树关键代码为Class1中的Open方法和GetTreeNode，如图8-5所示。

 

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;

namespace shiyan8
{
    public partial class Form5 : Form
    {
        public Form5()
        {
            InitializeComponent();
            this.Text = "递归挂树窗体";
        }

        private void Form5_Load(object sender, EventArgs e)
        {
            this.button1.Text = "递归挂树";
            this.button2.Text = "结束";
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Class1 class1 = new Class1();
            string xmlfilepath = "C:\\Users\\苗华\\source\\repos\\shiyan8\\shiyan8\\XMLFile1.xml";
            class1.Open(treeView1, xmlfilepath);
        }

        private void button2_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }
    }
}

 Class1文件：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Xml;

namespace shiyan8
{
    class Class1
    {
        public void Open(TreeView tv,String xmlFileName)
        {
            try
            {
                tv.Nodes.Clear();
                XmlDocument xml = new XmlDocument();
                xml.Load(xmlFileName);
                XmlNode root = xml.DocumentElement;
                TreeNode tn = new TreeNode();
                tn.Text = root.Name;
                tv.Nodes.Add(tn);
                GetTreeNode(root,tn);
            }
            catch(Exception ex)
            {
                throw ex;
            }
        }
        private void GetTreeNode(XmlNode xn,TreeNode tn)
        {
            foreach(XmlNode item in xn.ChildNodes)
            {
                TreeNode temp = null;
                if (item.HasChildNodes)
                {
                    temp = new TreeNode(item.Name);
                }
                else
                {
                    temp = new TreeNode(item.InnerText);
                }
                tn.Nodes.Add(temp);
                GetTreeNode(item, temp);
            }
        }
    }
}