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Custom application pages in the SharePoint 2010 Sandbox

Tags: Web Parts, SharePoint 2010

The Sandbox in SharePoint 2010 allows Site Collection administrators to upload solutions in their Site Collections without access to the physical server. This is a great way to open up for creativity and for each Site Collection owner to expand the functionality of their Site Collection without adventuring the stability of the SharePoint farm. Sandbox Solutions do have some limitations, for instance we cannot add new Application Pages. Application pages are normally pages added to the _layouts folder, which are located in the {SharePoint Root}\TEMPLATE\LAYOUTS physical folder on each server.

Application pages or similar are often used in different scenarios such as when you are building configuration or settings pages. I use them quite often and felt a bit limited with building Sandboxed solutions without them.

Sandboxed solutions still allows us to upload Content Pages, that is pages that are located in a document library for instance. So one workaround is to build a Web Part containing the custom logic and a Content Page that contains this Web Part. Then deploy this to the Solution gallery in your Site Collection. And this is how to do it:

Create a project

Create a new Empty SharePoint 2010 project using Visual Studio 2010 and deploy it as a Sandboxed solution.

Add a Web Part item

Solution ExplorerThen add a new Web Part item to your project. Remove the Web Parts Control Description file (.webpart) and the Elements.xml file. We do not want to add the Web Part to the Web Part gallery, this Web Part will only be used by our Sandboxed Application Page.

Then build your control logic in the Sandboxed Web Part.

Add a Module item

In the Web Part item add a new Module item. Rename the Sample.txt file to AdminPage.aspx or similar - just make sure the extension is .aspx. Your Solution Explorer should then look like the image to the right.

Edit the URL and location in the elements.xml file if you want to deploy it in a document library or any other location. If you have named your items as shown above your page will end up at http://site/AdminPage/AdminPage.aspx.

Edit the ASPX page

Open up the the AdminPage.aspx and build a standard Web Part Page. You can copy the source from a basic Web Part Page using SharePoint Designer for instance. The source should look something like this when you cleaned it up:

<%@ Page language="C#" 
<%@ Register Tagprefix="WebPartPages" Namespace="Microsoft.SharePoint.WebPartPages" 
  Assembly="Microsoft.SharePoint, Version=, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>

<asp:Content ContentPlaceHolderId="PlaceHolderPageTitle" runat="server">
Sandboxed Admin Page

<asp:Content ContentPlaceHolderId="PlaceHolderPageTitleInTitleArea" runat="server">
Sandboxed Admin Page

<asp:Content ContentPlaceHolderId="PlaceHolderAdditionalPageHead" runat="server">
<style type="text/css">
body #s4-leftpanel {
.s4-ca {

<asp:Content ContentPlaceHolderId="PlaceHolderLeftNavBar" runat="server">asp:Content>

<asp:Content ContentPlaceHolderId="PlaceHolderMain" runat="server">


In this Web Part Page I have removed all unnecessary page directives and only kept the Page directive with the master page reference and the import of the Microsoft.Sharepoint.WebPartPages namespace, which we will soon use. In the PlaceHolderAdditionalPageHead some CSS is added to remove the Quick Launch and I added a page title and heading.

Of course you can use any kind of HTML in here. You cannot use code-behind or inline server-side code though.

Add the Web Part

In the PlaceHolderMain the Web Part will be added. This is done by using the SPUserCodeWebPart, which is a wrapper for Web Parts that lives in the Sandbox. In my case it will look like this:

    ID="adminwp"     TypeFullName="Wictor.SBAppPage.AdminWebPart.AdminWebPart" >

Here we need to edit two things. First the TypeFullName must be the full name of your Web Part, just check the .cs file of your Web Part if you don't know how to get it. Secondly we need to set the SolutionId attribute to the solution id value of our solution. You can get a hold of this id by opening up the Package Editor and select Manifest. Then check the Solution element for the SolutionId attribute and just copy it.


The AssemblyFullName attribute contains a Visual Studio replaceable parameter which inserts the full name of your assembly.

Deploy and enjoy!

That's it - just deploy your solution and navigate to your custom sandboxed application page.

Ready for action!

No Comments

  • Trackback said

    The time has come for me to do my summary post of 2010. This is my fifth summary post (2006, 2007, 2008 and 2009). This year has been truly amazing. Working in the SharePoint world has been so interes...

  • Gary said

    I followed your guide and it was very helpful. The only issue is that after I deactivate and delete the solution, the content pages are left behind. Redeploying the solution (after deleting it) with changes to the content file do not get applied. So for now I am renaming the file every time I make a change. Any ideas? Thank you.

  • Skita said

    Hi: Once deployed the page shows this error, i have added the SolutionID from Package manifest file: Web Part Error: The request could not be completed because the specified solution was not found.

  • snreddy said

    ifollowed your guide and it was very helpful Nice post. The way you written is appreciated. and put your link here.

  • Stephan said

    I got the following error: Web Part Error: Unhandled exception was thrown by the sandboxed code wrapper's Execute method in the partial trust app domain: An unexpected error has occurred. In the link to SPUserCodeWebPart Class description on microsoft is a: Available in Sandboxed Solutions: No regards Stephan

  • Ankit Singh said

    This is one of the best articles so far I have read online. No crap, just useful information. Very well presented. Thanks for sharing with us. Check out this link too its also having a wonderful explanation on how to use custom application page in sharepoint... Thanks

  • Suraj said

    Hi Wictor, After deploying the sandboxed solution i am getting the following error: Web Part Error: Unhandled exception was thrown by the sandboxed code wrapper's Execute method in the partial trust app domain: The type is not registered as safe. Thanks, Suraj

  • Ravi said

    Hi Wictor,i have successfully deployed your illustrated example.but when it come to utilize my custom code it is giving me errors for all of asp textbox,labels and other controls.that the name does not exist in current context. any suggestion is highly appreciated..thanks

  • Justin said

    Thanks for the Article! I followed step by step and I am getting this error when I go to the page.

    Web Part Error: The request could not be completed because the specified solution was not found.

    Any ideas?


  • sam said

    I worked with tag prefix, it is working in pages but it is not working in masterPage. Its showing some error.. I follwed the same approch..its in 2013.

  • Suhil said

    Thanks for the post. I am using this code. But when I am trying to open the page which was designed , it shows Error " Web Part Error: Unhandled exception was thrown by the sandboxed code wrapper's Execute method in the partial trust app domain: The type is not registered as safe. "

    Can you plz help me get out of it.
    I have added safecontrols entry in "SPDataFile" , but still its shows the same error.

  • Ofer Gal said

    I get Web Part Error: Unhandled exception was thrown by the sandboxed code wrapper's Execute method in the partial trust app domain: The type is not registered as safe.

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About Wictor...

Wictor Wilén is the Nordic Digital Workplace Lead working at Avanade. Wictor has achieved the Microsoft Certified Architect (MCA) - SharePoint 2010, Microsoft Certified Solutions Master (MCSM) - SharePoint  and Microsoft Certified Master (MCM) - SharePoint 2010 certifications. He has also been awarded Microsoft Most Valuable Professional (MVP) for seven consecutive years.

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