Follow the below code or download the zipped code.

Here I am writing program to upload files into a folder and after it how to delete these files one by one.

.aspx code

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default2.aspx.cs" Inherits="Default2" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

<head id="Head1" runat="server">

<title></title>

</head>

<body>

<form id="form1" runat="server">

<div>

<asp:FileUpload ID="FileUpload1" runat="server" />

<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="upload" />

<br />

<br />

<br />

<br />

<asp:DropDownList ID="DropDownList1" runat="server">

</asp:DropDownList>

<asp:Button ID="Button2" runat="server" Text="delete" OnClick="Button2_Click" />

<br />

</div>

</form>

</body>

</html>

.cs code

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.IO;

public partial class Default2 : System.Web.UI.Page

{

protected void Page_Load(object sender, EventArgs e)

{

if (!Page.IsPostBack)

{

bind();

}

}

protected void Button1_Click(object sender, EventArgs e)

{

string silename = FileUpload1.FileName;

string path = Server.MapPath("~/upload/");

string fullpath = path + silename;

FileUpload1.SaveAs(fullpath);

bind();

}

public void bind()

{

DropDownList1.Items.Clear();

string path = Server.MapPath("~/upload/");

Directory.GetFiles(path);

foreach (var filenam in Directory.GetFiles(path))

{

string filename = filenam.ToString();

filename = filename.Replace(path, "").ToString();

DropDownList1.Items.Add(filename.ToString());

}

DropDownList1.DataBind();

}

protected void Button2_Click(object sender, EventArgs e)

{

string file = DropDownList1.SelectedItem.ToString();

string path = Server.MapPath("~/upload/");

string fullpath = path + file;

File.Delete(fullpath);

bind();

}

}