Increasing the Maximum file size for Web.Config


This can happen in any ASP.NET Web Application, but as Sitecore 8’s default web.config file is now 246 kb this makes it extremely susceptible to exceeding the default 250 kb limit.

To change the size limit you need to modify/create the following registry keys:

HKLM\SOFTWARE\Microsoft\InetStp\Configuration\MaxWebConfigFileSizeInKB  (REG_DWORD)

On 64-bit machines you may also have to update the following as well

HKLM\SOFTWARE\Wow6432Node\Microsoft\InetStp\Configuration\MaxWebConfigFileSizeInKB (REG_DWORD)

You will probably find that these keys need to be created, rather than just being updated. After changing them you will also need to reset IIS.


Alternatively you can leave the default values at 250 kb and split the web.config files into separate files.

More information on doing this can be found here:

My personal preference for Sitecore projects is to update the the max file size as this allows keeping the web.config file as close to the default install as possible. The benefit of doing this is it makes upgrades easier, rather than needing to know why your web.config doesn’t match the installation instructions.


Creating 301 redirects in web.config

For various reasons at times you may need to create a 301 redirect to another URL. This could be as a result of a page moving or you just need to create some friendly URLS.

As a developer you may be tempted to do something like this in code…

private void Page_Load(object sender, System.EventArgs e)
    Response.Status = "301 Moved Permanently";

But do you really want your project cluttered up with files who’s only purpose is to redirect to another page!

You may also be tempted to try doing something with .NET’s RouteCollection. This would certainly solve an issue on creating a redirect for anything without a file extension, but there is a better way.

In your web.config file under the configuration node create something like this

  <location path="twitter">
      <httpRedirect enabled="true" destination="" httpResponseStatus="Permanent" />

The location path specifies that path on your site that this redirect will apply to. The destination value in the httpRedirect is where the redirect will go to. As well as setting Permanent for the httpResponseStatus you can also specify Found or Temporary depending on your needs.

ASP.NET Session Timeout

A users session on an ASP.NET site by default will time-out after 20 minutes. This however can be changed through either the web.config file or IIS.

To edit through the web.config file you need to edit the sessionState tag under system.web

  <sessionState timeout="30"></sessionState>

Or through IIS click on your site name and then click Session State under the ASP.NET heading. There will be a field labeled Time-out (in minutes).

The value you enter for time-out must be an integer.

Help it doesn’t seem to work!

If your sessions still seem like there timing out after 20 minutes it could be because your site isn’t very active.

The application pool for your site also has an idle time-out that is set by default to 20 minutes. When the idle time-out is reached it will cause your application pool to recycle and therefore loose any active sessions (that’s assuming you have the session state mode set to In Proc). Therefore it is a good idea to increase this to whatever you have set the session time-out to.

To do this go to your sites application pool in IIS, click advanced settings on the right and then look for the Idle Time-out (minutes) setting and update this to be the same as your session time-out value.

Converting users from Membership to SimpleMembership

In ASP.NET 2 Microsoft introduced the Membership provider. By many accounts it is not perfect, but as a one size fits all solution it’s not bad. Plus it had a major advantage that a lot of other people would also be using it, so if you wanted to grab a forum solution to stick on your site, chances were it would use the same Membership provider.

Now though there is a second Membership provider from Microsoft called SimpleMembership. It simplifies a lot of things that weren’t needed with the original Membership provider and also introduces support for working with OAuth providers. Not only that but if you create the MVC 4 project from the default template that is what your solution will be set up to use.

The problem however is Membership and SimpleMembership are not compatible. They store their information in separate tables and if you do try to copy all the users from one to the other, you will soon discover the hashing algorithm used on the password is different. You probably also had all your passwords one way hashed so you can’t even generate the new ones.

There is a solution however. Paul Brown has written a nice bit of code to update the MVC 4 account controller so that when your users log in they will first be authorised against SimpleMembership, if that fails it will then authorise against the original Membership and if that succeeds it will generate the new password in SimpleMembership using the one just provided by the user.

Over time as your users log in the will be slowly migrated over. The second time the log in the SimpleMembership will authorise them and the extra code won’t even be hit.

Image resizing

Using 3rd party components while essential, can also be a headache. All to often you can find yourself spending hours following the setup instructions to the letter only for it to not work. Other times you know it’s the exact component you want to use but it seems while the guys may have spent a huge effort in writing to component they seemingly never got round to writing anything to tell you how to use it.

Every so often though I come across a component that works first time and does exactly what you want. One such component that I’ve found this with recently ImageResizer.

I needed a simple way for images to be resized for a product listing on an eCommerce platform written in Classic ASP. Image resizing can be a real pain, there’s the decision of do you do it when the images are uploaded or on the fly, if you do it on the fly there’s a a huge number of mistakes you can make and nearly every example of how to do image resizing includes a couple of them. Then lastly in either scenario you need to make sure the end result is actually decent quality.

With image resizer I was done in 5 minutes! It’s actually a .net component rather than Classic ASP but that wasn’t an issue. You create a bin folder, add a couple of simple lines to your web.config file then put an extra extension on the image path plus parameters for the size you want and that’s it!

If your doing a .net project it’s also available on NuGet making it even easier to get up and running.

.Net Tip: Default Button for Enter Key

I don’t know if I should be happy to now know about this, or just conserned that it’s taken me this long to discover. But one issue that surfaces time and time again when programming in ASP.NET, is that issue that pressing enter/return in a text feild doesn’t always do what you want it to do. 

On a normal website you can have many forms each with their own submit button which becomes the default action when pressing return on one of the forms feilds. However in ASP.NET Web Forms there is only ever one form on a page, but there could be 10 different buttons each needing to be the default action for a particular text box. 

The solution as it turns out is very simple and you have two options both introduced in .NET 2.0 (yes that’s how old it is!) 

1. Default button for the form. If your page has more than one button, but there is only one that you want to fire when you hit enter then in the code behind you can just type… 

Form.DefaultButton = Button1

or it can also be specified in your aspx file 

<form runat="server" defaultbutton="Button1">

2. If you need to be more specific a panel can also have a default button… 

Panel1.DefaultButton = Button1

or again is can be specified in your aspx file

<asp:Panel runat="server" DefaultButton="Button1">

Custom Validator Error from Server Side

The built in ASP.NET validators are amazing as we all know. You just drag them on the page, tell them what control to validate, give them a summary control to list the errors and they do it. But what if there’s something you need to add server side? Such as something that needs to check with the database before saving. You already have your validation summary control, so it would be nice to re-user that and have everything automatically looking the same. But it would appear there’s no easy way of doing it built in, so here’s an easy way of doing it… 

Creating a Custom Validation Error

First your going to need a class with some static class’s that you can pass your error message to. Here I have two functions one for simply adding the error to the page and the other for adding the error to the page with a specific validation group. I am using a CustomValidator object to make this all work, another option is to implement IValidator but it’s actually more effort than’s needed. The other section to note is that I’m setting the Error.Text to a non breaking space (this is what would normally go next to the form field you’re validating). This is because if you don’t then it will default to the ErrorMessage which we only want to go into the summary. If you try setting it to a normal space it will still also default to the summary text.

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

/// <summary>
/// Summary description for Validator
/// </summary>
public class ValidationError

    public static void Display(string Message)
        Display(Message, "");

  public static void Display(string Message, string ValidationGroup)
  CustomValidator Error = new CustomValidator();
        Error.IsValid = false;
        Error.ErrorMessage = Message;
        Error.ValidationGroup = ValidationGroup;
        Error.Text = "&nbsp;";

  Page currentPage = HttpContext.Current.Handler as Page;

Now to trigger the error you just need to called the function as below:

ValidationError.Display("Useful error message", "ValidationGroupName");

Creating Events in ASP.NET

Creating your own events on your own controls is something that is essential if you want you web app to work well and also provide you with reusable controls. It’s easy to skip past the problem and find another way to get your code to do what you want it to do and detect the change another way. But you end up with much nicer code if your controls can have proper events for a piece of action, and you web page can have proper event handlers on each. Not only that but the code you need to write in generally a copy and past job and not that hard.

The Code

While it’s not that hard, the amount of code that is needed is quite a lot more than you may expect. Fortunately though it’s code you going to just re-use again and again changing small bits as needed.

    //1 - Event args (use default, but eventually pass in data through here)
    public class SaveCompleteEventArgs : EventArgs
        public SaveCompleteEventArgs(int inDataValue)
            this.DataValue = inDataValue;
        } //end of con

        public readonly int DataValue;

    //2 - define delegate
    public delegate void SaveCompleteEventHandler(object sender, SaveCompleteEventArgs e);

    //3 - define the event itself
    public event SaveCompleteEventHandler SaveComplete;

    //4 - the protected virtual method to notify registered objects of the request
    //	virtual so that it can be overridden.
    protected virtual void OnSaveComplete(SaveCompleteEventArgs e)
        //if the UpdateData event is empty, then a delegate has not been added to it yet.
        if (SaveComplete != null)
            //event exists, call it:
            SaveComplete(this, e);
        } //end of if

    //5 - method that translates the input into the desired event
    public void TriggeringMethod(int strData)

        // get new event args
        //EventArgs e = new EventArgs();
        SaveCompleteEventArgs e = new SaveCompleteEventArgs(strData);

        // call the virtual method


Lazy loading isn’t a new concept, it’s a pattern that been around for a while to improve the performance of your apps by only loading objects when they are going to be used. For example if you have an object that contains a property of a list of customers then you only really need to populate it when you access the property not when the object was initially created, as it may never be used. At the same time though you don’t want to be going off to the database every time access the property. So the simple solution is to have another private variable that stores if the customers property is populated or not and then check that in the property’s get to determine if the data needs to be loaded or not.

Well now in .NET 4, lazy loading has been built into the framework with System.Lazy. Instead of the above all you need to do now is write something like this…

Lazy<Customers> _customers = new Lazy<Customers>();

What this will do is create you a customers object but only run the constructor when you actually access the objects Value property which will be of type Customers. e.g.


It’s that simple, but can get even better. The constructor may not be the only thing you want to run when you access the property the first time. In this case you would write something like…

_customers = new Lazy<Customers>(() =>
            // Write any other initialization stuff in here
            return new Customers();

I must point out though while as great as this is, it does have some limitations so you probably won’t want to use it in all scenarios.

For more information check out the Lazy initialization page on MSDN