FileUpload : Page Cannot be displayed and maximum request length exceeded error

By default, ASP.NET permits only files that are 4,096 kilobytes (KB) or less to be uploaded to the Web server.  To upload larger files, we must change the maxRequestLength parameter of the <httpRuntime> section in the Web.config file. By default, the <httpRuntime> element is set to the following parameters in the Machine.config file:

<httpRuntime

executionTimeout=90

maxRequestLength=4096

useFullyQualifiedRedirectUrl=false

minFreeThreads=8

minLocalRequestFreeThreads=4

appRequestQueueLimit=100

/>

We can change the value of maxRequestLength to a desired value in our web.config of the application. For 10 mb we can set it to 10240 KB. Even in this case if user tries to upload a file with size more than 10 mb we than get the above “Page cannot be displayed error ” or the page simply hang up. In this case we can catch the error in the Application_Error event handler of the Global.asax file.

void Application_Error(object sender, EventArgs e)

{

if (System.IO.Path.GetFileName(Request.Path) == “Default.aspx”)

{

System.Exception appException = Server.GetLastError();

if (appException.InnerException.Message == “Maximum request length exceeded.”)

{

Server.ClearError();

Response.Write(“The form submission cannot be processed because it exceeded the maximum length allowed by the Web administrator. Please resubmit the form with less data.”);

Response.Write(“<BR><a href=’Default.aspx’>Click Here to go back to page</a> </BR>”);

Response.End();  } } }

I tried with the above code, but it isn’t consistent.

The best solution for this could be to set the value of maxRequestLength to a very high value.

and checking in the code for the size.

Say changing the value to say 700mb ( not sure what the maximum length of request could be)

<httpRuntime useFullyQualifiedRedirectUrl=true

maxRequestLength=716800

/>

And checking for the length in your code

// Putting the constraint of 1 mb

if (FileUpload1.FileContent.Length < 1024){

FileUpload1.SaveAs(@”C:/MyFolder/” + FileUpload1.FileName);}

else{

return;}

At least the above solution would save us from the page not displayed error.

And the last solution which i found was creating an httpmodule to intercept the web request.

using System;

using System.Collections.Generic;

using System.Text;

using System.Web;

namespace HAMModule{

public class MyModule : IHttpModule{

public void Init(HttpApplication app){

app.BeginRequest += new EventHandler(app_BeginRequest);

}

void app_BeginRequest(object sender, EventArgs e){

HttpContext context = ((HttpApplication)sender).Context;

// check for size if more than 4 mb

if (context.Request.ContentLength > 4096000){

IServiceProvider provider = (IServiceProvider)context;

HttpWorkerRequest wr = (HttpWorkerRequest)provider.GetService(typeof(HttpWorkerRequest));

// Check if body contains data

if (wr.HasEntityBody()){

// get the total body length

int requestLength = wr.GetTotalEntityBodyLength();

// Get the initial bytes loaded

int initialBytes = wr.GetPreloadedEntityBody().Length;

if (!wr.IsEntireEntityBodyIsPreloaded()){

byte[] buffer = new byte[512000];

// Set the received bytes to initial bytes before start reading

int receivedBytes = initialBytes;

while (requestLength – receivedBytes >= initialBytes){

// Read another set of bytes

initialBytes = wr.ReadEntityBody(buffer, buffer.Length);

// Update the received bytes

receivedBytes += initialBytes;

}

initialBytes = wr.ReadEntityBody(buffer, requestLength – receivedBytes);}}

// Redirect the user to an error page.

context.Response.Redirect(“Error.aspx”);}}

public void Dispose(){}

}}

and add the following information to web.config

<httpModules>

<add type=HAMModule.MyModule name=MyModule/>

</httpModules>

inside

<system.web>

The last solution worked properly!!!!

BeginRequest event –The BeginRequest event signals the creation of any given new request. This event is always raised and is always the first event to occur during the processing of a request.

Article on creating a custom http module

http://msdn.microsoft.com/en-us/library/ms227673(VS.80).aspx


Bye..


Author: Nishant Rana

I love working in and sharing everything about Microsoft.NET technology !

8 thoughts on “FileUpload : Page Cannot be displayed and maximum request length exceeded error”

  1. Awesome, fixed my problem by just adding this web.config

    and these lines to upload event
    if (fulAttachFile.PostedFile.ContentLength >= 4194304)
    {
    cstnVldErrorMaxFileSize.IsValid = false;
    return;
    }

    Thanks a lot

    Like

  2. Well, code is nice. Have seen it on different places on the web.
    But it’s still not working for me. Can’t get it to work.
    Got the same error as coder3000: “Page cannot be displayed”

    Like

  3. Quoted from Chris Hynes (http://stackoverflow.com/questions/674651/uploading-files-past-asp-net-request-length-limit)

    “Because of the nature of HTTP, you can’t actually return anything until you read all the request data. When you receive an oversized request, you have two options:

    Read in all the data and then return a nice error page. This sounds good, but means the user has to wait for the upload to complete before he gets the message that he can’t upload. It also opens a possible DOS attack hole.

    Terminate the request immediately. This gives the user a crappy disconnect page, but preserves security.

    There is a third option — use an advanced component that provides both nice error messages as well as security. You can use flash only components, and there are many of them out there, but of course, if the user doesn’t have flash, you’re out of luck.”

    Like

  4. I tried these steps and am still getting “Page cannot be displayed” error. Basically I want to stop the upload if the content length is above a certain value. Doing any kind of response.end, etc. causes “Page cannot be displayed”. Is there a way to show a friendly error about this to the user?

    I would appreciate any tips on this.

    Thanks!

    Like

Share your thoughts

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s