Restrict User to Upload only specific type of files in ASP.NET

Updated on September 22, 2015     Kisan Patel

This tutorial will show you how to restrict the user to upload only specific type of files (.gif, .png or .jpg file) in ASP.NET?

Default.aspx

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

<p><asp:Button ID="Button1" OnClick="UploadFile" runat="server"
Text="Upload Specific Type of File" />

Default.aspx.cs

Namespace:

using System.IO.Path.GetExtension;

Code:

protected void UploadFile(object sender, EventArgs e)
{
      string fileName = FileUpload1.PostedFile.FileName;
      string extension = Path.GetExtension(fileName);
      if (extension.Equals(".jpg") || extension.Equals(".gif") || extension.Equals(".jpg"))
      {
          string path = Server.MapPath("~/images/");
          FileUpload1.SaveAs(path + fileName);
          Response.Write("File uploaded successfully !");
      }
      else
      {
          Response.Write("upload only .jpg, .gif or .png file!");
      }
}