ASP.NET中对文件的操作 创建 读取 删除 上传 下载

1.创建文件并写入内容

记得导入命名空间Imports System.IO

Sub CreateWriteFile() '创建文件

Response.Write("Writing　the　content　into　Text　File　in　ASP.NET　<BR>")

'　声明streamwriter对象

Dim strwriterobj As StreamWriter

'创建文本文件并将其赋给上面声明的streamwriter对象

strwriterobj = File.CreateText("c:\aspnet.txt")

'在刚才创建的文本文件里写一些东东　

strwriterobj.WriteLine("Welcome　to　user　chenyang's　ASP.NET　Program")

strwriterobj.Close()

Response.Write("创建文本文件并填充内容")

End Sub
2.读取文件内容

Sub ReadFile() '读取文件

Response.Write("读取asp.net文件中的内容 <br>")

'声明一个StreamReader对象

Dim streamreaderobj As StreamReader

'声明一个变量保存读出的内容

Dim filecont As String

'打开文件赋值到StreamReader对象

streamreaderobj = File.OpenText("c:\aspnet.txt")

'按行循环读取文件内容

Do

filecont = streamreaderobj.ReadLine()

If filecont = "" Then

Response.Write(filecont)

Else

Response.Write(filecont & "<br>")

End If

Loop Until filecont = ""

'关闭StreamReader对象

streamreaderobj.Close()

Response.Write("<br> 已经读完aspnet.txt文件的内容")

End Sub
3.删除文件

Sub DeleteFile() '删除文件

File.Delete("c:\aspnet.txt")

Response.Write("文件删除成功!!!")

End Sub
4.上传文件

附件<a name="anchor1"></a>

<asp:FileUpload ID="FileUpload1" runat="server" TabIndex="4" Width="300px" />

<asp:Button ID="cmdSaveAttachment" runat="server" CssClass="button" TabIndex="5"

Text="保存附件" />

Protected Sub saveAttachment()

If FileUpload1.HasFile Then

'获取网站根目录路径

Dim path As String = HttpContext.Current.Request.MapPath("../UploadFile/")

FileUpload1.SaveAs(path & FileUpload1.FileName)

Else

Response.Write("<script language='javascript'>alert('请先选择附件 ');</script>")

End If

End Sub
5.下载附件

在文本上加上地址连接即可

Label1.Text = "<a href=' ../UploadFile/TextFile.txt ' target='_blank'> TextFile.txt </a>    "