Restrict User to Upload Only doc or .docx Using Fileupload in Asp.Net C#.Net

This article I will use to explain you how you can restrict user to upload only .doc or .docx file in asp.net using c#.net. In this we will do server side validation before uploading file.

Some of my previous articles are as follows: File Upload in MVC3 By Using Razor, Multiple File Upload With Asp.Net MVC C# and HTML5 | How to upload files to ASP.NET MVC application, How to Get the Full Path of FileUpload Control in Asp.Net, How To Get File Size Uploaded By FileUpload Control Using C# In Asp.Net, File Upload with ASP.NET | How to Use FileUpload Control in ASP.Net Using C#.Net,VB.Net | Upload File in Asp.net and Save in Folder, File Upload in C#.Net Windows Application.

So for this article first we will create a new asp.net application.  Now in page a we will add fileupload control , button control and label control to display message. Here is the html code.

<div>         <h2>        <asp:Label ID="lblmessage" runat="server" Style="color: #FF0000; font-size: small;" Text=""></asp:Label>         </h2>         Upload File :<asp:FileUpload ID="FileUpload1" runat="server" />         (upload .doc,.docx)<br />         <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Upload" />     </div>

Now generate button control and add the below code.

using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; namespace UploadFileinAsp.net {     public partial class _Default : System.Web.UI.Page     {         protected void Page_Load(object sender, EventArgs e)         {         }         protected void Button1_Click(object sender, EventArgs e)         {             if (FileUpload1.HasFile)             {                 string fileextention = System.IO.Path.GetExtension(FileUpload1.FileName);                 if (fileextention == ".doc" || fileextention == ".docx")                 {                     string filename = System.IO.Path.GetFileName(FileUpload1.FileName);                     FileUpload1.SaveAs(Server.MapPath("~/document/" + filename));                     lblmessage.Text = "File uploaded successfully.";                 }                 else                 {                     lblmessage.Text = "You are allowed to upload only .doc or .docx file.";                 }             }         }     } }

In above code first we have find the extension of the file and after that we are validating the file type. If file type in .doc or .docx on that case we are allow to upload file otherwise we are displaying error message.

Now run the page.  First we will select pdf file and click on upload. We will get error message.

Now select .pdf file

 Now click on

Now we will select word document and click on upload. We will get successful upload message.

Now select doc file

DOWNLOAD