file upload validation in asp.net c#

Category > ASP.NET || Published on : Monday, November 11, 2019 || Views: 86 || file upload validation fileupload required validation


Here Pawan Kumar will explain how to do fileupload required validation in asp.net using required field validator control

Method 1 - fileupload required validation in asp.net using required field validator control

  • Step 1 - Create a new asp.net website using Visual Studio 2019 or any other version
  • Step 2 - Add a new Webform C# into the website we have create in previous step.
  • Step 3 –Now add the below codes to achive “ required validation on file upload control in asp.net“ functionality

DEMO VIDEO

fileuploadaspnet.aspx

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

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title>asp.net FileUpload validation example: how to validate FileUpload control (file upload)</title>
</head>
<body>
    <form id="form1" runat="server">
        <div>
            <h2>asp.net FileUpload example: file upload validation in asp.net c#
            </h2>
            <asp:Label ID="Label1" runat="server">
            </asp:Label>
            <br />
            <br />
            <asp:Label ID="Label2" runat="server" Text="Choose a file for upload it." Font-Bold="true">
            </asp:Label>
            <br />
            <asp:FileUpload ID="FileUpload1" runat="server" />
            <asp:RequiredFieldValidator
                ID="RequiredFieldValidator1" runat="server" ControlToValidate="FileUpload1" ErrorMessage="Choose a file!">
            </asp:RequiredFieldValidator>
            <br />
            <asp:Button ID="Button1" runat="server" Font-Bold="true" OnClick="Button1_Click" Text="Upload Now" />
            <br />
            <br />
        </div>
    </form>
</body>
</html>

fileuploadaspnet.aspx.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class fileupload_fileuploadaspnet : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }

    protected void Button1_Click(object sender, EventArgs e)
    {
        string uploadFolder = Request.PhysicalApplicationPath + "\\Upload\\";
        FileUpload1.SaveAs(uploadFolder + FileUpload1.FileName);
        Label1.Text = "File uploaded successfully: " + FileUpload1.PostedFile.FileName;
    }
}

We have also added the source code for file upload in asp.net with validation. You can freely use these source codes.

Method 2 - fileupload validation in asp.net using javascript

In method two We will shows you how to validate a file extension in ASP.NET using JavaScript.

Now  create a JavaScript function to ensure that only the specified extension is valid. First of all you start Visual Studio .NET and make a new ASP.NET web site using Visual Studio 2019.

Below is the code for fileupload required validation in asp.net using javascript

  1. Step 1 - Create a new asp.net website using Visual Studio 2019 or any other version
  2. Step 2 - Add a new Webform C# into the website we have create in previous step.
  3. Step 3 –Now add the below codes to achive “fileupload control in asp.net javascript validation “ functionality

fileupload-method-2.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="fileupload-method-2.aspx.cs" Inherits="fileupload_method_2" %>

<!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 runat="server">
    <title></title>
    <script type="text/javascript">
        function validate() {
            var array = ['pdf', 'doc', 'docx', 'txt', 'xlsx', 'ppt', 'zip'];
            var xyz = document.getElementById("FileUpload1");
            var Extension = xyz.value.substring(xyz.value.lastIndexOf('.') + 1).toLowerCase();
            if (array.indexOf(Extension) <= -1) {
                alert("Please Upload only pdf,doc,zip,txt.xlsx and ppt extension flle");
                return false;
            }
        }
    </script>
</head>
<body>
    <form id="form1" runat="server">
        <div>
            <asp:FileUpload ID="FileUpload1" runat="server" />
        </div>
        <asp:Button ID="Button1" runat="server" Text="Button" OnClientClick="return validate();" />
    </form>
</body>

</html>

Hope, Both these two methods will help you provide file upload required features as well as provide the client side validation for fileupload asp.net control.

Download Source Codes