Restrict User to Upload File of a Specific Size in Asp.Net Using C#.Net

This article will show you how you can restrict user to upload file of a specific size in asp.net using c#.net on server side.

Some of my previous articles are as follows: Ajax FileUpload Control In Asp.Net or Multiple FileUpload With Progress Example in Asp.Net Using C#.Net, 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, 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, Restrict User to Upload Only doc or .docx Using Fileupload in Asp.Net C#.Net.

For this article first we will create a new asp.net application and add fileupload control and a button control.

<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" />         <br />         (allowed only max 2MB to upload) <br />         <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Upload" />     </div>

Now we will create the button click event by clicking on button control. Now use 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)             {                 /*1MB=1024KB*/                 long filesize = ((FileUpload1.PostedFile.ContentLength) / 1024) / 1024;                               if (filesize < 2)                 {                     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 more then 2MB.";                 }             }         }     } }

In above code we have get the uploaded file size by FileUpload1.PostedFile.ContentLength.  After getting file size we converted the byte into MB by dividing 1024. So we have done with code. Now run the page.

But before this we will make a configuration change. Add the below setting in web.config.

<system.web>   <httpRuntime executionTimeout="240" maxRequestLength="20480" /> </system.web>

Have a look of the file size we are going to upload whose size is 4MB.

Now we will select the file click on browse button and click on upload .

 Now have a look of the file of size less than 2MB.

Now select file and click on upload.

Now click on upload after selecting file.

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