ASP.NET对文件的操作，创建文件，判断文件是否存在，判断文件是否存在删除文件夹

操作文件必须引入using System.IO;命名空间

//获取一个文件的大小 System.IO.FileInfo file = new System.IO.FileInfo("C:\\t.txt"); int fileSize = (int)file.Length / 1024;//把文件大小换算成KB Response.Write("<script>alert(" + fileSize.ToString() + ");</script>");

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-------创建文件夹using System.IO; private void button2_Click(object sender, EventArgs e) { if (Directory.Exists("\\picture"))//判断一个文件夹是否存在 { MessageBox.Show("directory exists"); } else {

　　　　//创建一个文件夹 Directory.CreateDirectory("\\picture"); } }

Directory.Delete(path,true);//删除一个文件夹，其中path是文件夹的绝对路径

---------------------打开一个文件

Process.Start("C:\\t.txt");//打开一个文件

public void Page_Load(Object src,EventArgs e) { StreamWriter rw = File.CreateText(Server.MapPath(".")+"\\myText.txt"); rw.WriteLine("追逐理想"); rw.WriteLine("kzlll"); rw.WriteLine(".NET笔记"); rw.Flush(); rw.Close(); } 打开文本文件 StreamReader sr = File.OpenText(Server.MapPath(".")+"\\myText.txt"); StringBuilder output = new StringBuilder(); string rl; while((rl=sr.ReadLine())!=null) { output.Append(rl+"<br>"); } lblFile.Text = output.ToString(); sr.Close();

C#追加文件 StreamWriter sw = File.AppendText(Server.MapPath(".")+"\\myText.txt"); sw.WriteLine("追逐理想"); sw.WriteLine("kzlll"); sw.WriteLine(".NET笔记"); sw.Flush(); sw.Close(); C#拷贝文件 string OrignFile,NewFile; OrignFile = Server.MapPath(".")+"\\myText.txt"; NewFile = Server.MapPath(".")+"\\myTextCopy.txt"; File.Copy(OrignFile,NewFile,true); C#删除文件 string delFile = Server.MapPath(".")+"\\myTextCopy.txt"; File.Delete(delFile); C#移动文件 string OrignFile,NewFile; OrignFile = Server.MapPath(".")+"\\myText.txt"; NewFile = Server.MapPath(".")+"\\myTextCopy.txt"; File.Move(OrignFile,NewFile); C#创建目录 // 创建目录c:\sixAge DirectoryInfo d=Directory.CreateDirectory("c:\\sixAge"); // d1指向c:\sixAge\sixAge1 DirectoryInfo d1=d.CreateSubdirectory("sixAge1"); // d2指向c:\sixAge\sixAge1\sixAge1_1 DirectoryInfo d2=d1.CreateSubdirectory("sixAge1_1"); // 将当前目录设为c:\sixAge Directory.SetCurrentDirectory("c:\\sixAge"); // 创建目录c:\sixAge\sixAge2 Directory.CreateDirectory("sixAge2"); // 创建目录c:\sixAge\sixAge2\sixAge2_1 Directory.CreateDirectory("sixAge2\\sixAge2_1");