Error: The type or namespace name ‘xxx’ could not be found

Today I ran into a small programming related issue. As I was working on a webpart, I was trying to use an UpdatePanel control. So I referenced the System.Web and added the using statements:

  • using System.Web;
  • using System.Web.UI;

But still got me the nasty The type or namespace name ‘UpdatePanel’ could not be found (are you missing a using directive or an assembly reference?) 

Well of course not I added all the needed directives and assemblies. Or didn’t I?

UpdatePanel is an extension, it used to be in the Atlas library which later became Ajax.NET so don’t forget to also reference System.Web.Extensions. This should solve your problems. As it is plain .NET code it is something that works in SharePoint as well as other .NET applications.

Can be a tricky little thing, and of course it doesn’t only go for the update panel but for all the Ajax controls.

So that’s it for now, hope to see you soon, untill then happy SharePointing.

Error: The Web application at http://localhost/ could not be found

Ok, so I’ve run into the first (small) problem. As I was working on a small tool (which is supposed to solve another small problem I ran into), which retrieves all lists in a certain web, I immediately ran into a problem. Figures, problems with the first line of code. Good excuse to post some code and try this wp-plugin. As I am pretty new to this SharePoint coding, I am open for suggestions and tips and will adjust articles and code accordingly.

 C# |  copy code |? 
            using (SPSite site = new SPSite("http://localhost/"))
                 using (SPWeb web = site.OpenWeb(""))
                     foreach (SPList l in web.GetListsOfType(SPBaseType.GenericList))
                         Guid myGuid = l.ID;
                         string strName = l.Title;

I got the following error message:

The Web application at http://localhost/ could not be found. Verify that you have typed the URL correctly. If the URL should be serving existing content, the system administrator may need to add a new request URL mapping to the intended application.

The solution was very simple, the target platform is x64 while a new project by default targets x86. So go to the menu Build -> Configuration Manager and change the active platform to x64.