Add "FlashUpload.dll" to Bin folder of ASP.Net.

Upload.cs class

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.SessionState;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.IO;

public class Upload : IHttpHandler, IRequiresSessionState
{

public bool IsReusable
{
get { return true; }
}
public void ProcessRequest(HttpContext context)
{
if ( context.Request.Files.Count > 0 )
{
for(int j = 0; j < context.Request.Files.Count; j++)
{
HttpPostedFile uploadFile = context.Request.Files[j];
if (uploadFile.ContentLength > 0)
{
uploadFile.SaveAs(context.Server.MapPath("~/Uploads/"+uploadFile.FileName));
}
}
}
}

}

Web.config

In <system.web> of config file add the following tags
<httpHandlers>
<!--

The httpHandler that files are uploaded to, defined in App_Code/Upload.cs
-->
<
remove verb="POST,GET" path="Upload.cs"/>
<add verb="POST,GET" path="Upload.cs" type="Upload"/>
</httpHandlers>
<!--

The maximum files size allowed
-->
<
httpRuntime maxRequestLength="1550000"/>
<customErrors mode="Off" />

Default.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" EnableEventValidation="false" %>
<%@ Register Assembly="FlashUpload" Namespace="FlashUpload" TagPrefix="FlashUpload" %>

<!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>Untitled Page</title>
</head>
<
body>
<form id="form1" runat="server">
<div>
<asp:LinkButton ID="LinkButton1" runat="server"
Visible="False">LinkButton</asp:LinkButton>
<br />
<FlashUpload:FlashUpload ID="flashUpload" runat="server"
UploadPage="Upload.cs" OnUploadComplete="UploadComplete()"
FileTypeDescription="Images"
FileTypes="*.*"
UploadFileSizeLimit="1800000" TotalUploadSizeLimit="2097152" />
</div>
</form>
</body>
</html>

Default.aspx.cs

using System;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;

public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
string jscript = "function UploadComplete(){" + ClientScript.GetPostBackEventReference(LinkButton1, "") +"};";
Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "FileCompleteUpload", jscript, true);
}
}
}


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