Introduction

This article explains how to delete a file, of files listed in a DropDownList, existing in a folder.

Add the following namespaces in the .cs file:

  1. using System;
  2. using System.Drawing;
  3. using System.IO;
I have files in my application folder; the folder is named "files". I want to delete some file from those so first I list all the file names in a dropdown list. Write the following code in the .aspx page:

  1. <html xmlns="http://www.w3.org/1999/xhtml">
  2. <head id="Head1" runat="server">
  3. <title>how to delete a file from a folder in ASP.Net using C#</title>
  4. <style type="text/css">
  5. .auto-style1 {
  6. width: 88px;
  7. }
  8. </style>
  9. </head>
  10. <body>
  11. <form id="form1" runat="server">
  12. <div>
  13. <table>
  14. <tr>
  15. <td>Select file to delete</td>
  16. <td class="auto-style1">
  17. <asp:DropDownList ID="DropDownList1" runat="server" Height="16px" Width="88px">
  18. <asp:ListItem>Select file</asp:ListItem>
  19. <asp:ListItem>file1.txt</asp:ListItem>
  20. <asp:ListItem>file2.pdf</asp:ListItem>
  21. <asp:ListItem>file3.doc</asp:ListItem>
  22. <asp:ListItem></asp:ListItem>
  23. </asp:DropDownList>
  24. </td>
  25. </tr>
  26. <tr>
  27. <td></td>
  28. <td class="auto-style1">
  29. <asp:Button ID="btnDelete" runat="server" Text="Delete" OnClick="btnDelete_Click" />
  30. </td>
  31. </tr>
  32. <tr>
  33. <td colspan="2">
  34. <asp:Label ID="lbl_output" runat="server" /></td>
  35. </tr>
  36. </table>
  37. </div>
  38. </form>
  39. </body>
  40. </html>
Code.cs

When the dropdown has all file names you can select any file to be deleted and click on the button "Delete". It will check if the file exists; if it exists then it will delete file else show you a message in the lbl_output that your file does not exist.

Write the following code on the button delete:
  1. protected void btnDelete_Click(object sender, EventArgs e)
  2. {
  3. string file_name = DropDownList1.SelectedItem.Text;
  4. string path = Server.MapPath("files//" + file_name);
  5. FileInfo file = new FileInfo(path);
  6. if (file.Exists)//check file exsit or not
  7. {
  8. file.Delete();
  9. lbl_output.Text = file_name + " file deleted successfully";
  10. lbl_output.ForeColor = Color.Green;
  11. }
  12. else
  13. {
  14. lbl_output.Text = file_name + " This file does not exists ";
  15. lbl_output.ForeColor = Color.Red;
  16. }
  17. }
Save all and view the page in the browser; it will work fine.