Class could not be found?

Question

I have a asp.net Web Site Project that I am migrating to a Web Application Project. Most of the forms in this project are derived from a base class, but for some reason after the migration, the base class is not being found. My base class is in the following folder: App_Code/BaseClasses/BasePage.cs and is defined as follows:

//more stuff above
using System.Web;

public class BasePage : Page
{
    public BasePage()
    {
    }
    protected override void OnInit(EventArgs e)
    {
       //whatever
    }
    //some other stuff
}

And my forms are in a variety of folder and they use the base class like so:

//More stuff above
using System.Web;
                                       //Derived from base page
public partial class Reports_Uploads : BasePage
{
    //a bunch of stuff
}

Any time I try to derive from the base page I get the following error:

Error 166 The type or namespace name 'BasePage' could not be found (are you missing a using directive or an assembly reference?)

I tried wrapping both in the same namespace, but that didn't make any difference. There are not any errors on BasePage when I attempt to compile. Can anyone see why this would be happening?

Is BasePage `included` in the project or just in the folder? i.e. Do you see it in Visual Studio in the project, or did you just copy the file? Also, So are they now inside a namespace (and the same one)? — ispiro, Aug 24 '15 at 23:20
Just to clarify - you are asking if it is actually "included" in the visual studio project correct (rather than just sitting on the file system)? If that is what you are asking then yes, it's included. That's how I know there aren't any errors when I compile. — Abe Miessler, Aug 24 '15 at 23:23
Regarding the namespace issue - I think you might be right but I am not positive. If that's the case I will add it later, but for my current issue - wrapping both the base class and the derived class in the same namespace should fix the `'BasePage' could not be found` error i'm getting, correct? — Abe Miessler, Aug 24 '15 at 23:26
Assuming that when you click F12 ("go to definition") on BasePage that's on the line: `public partial class Reports_Uploads : BasePage` and it shows you that class - perhaps all you need to do is clean the solution and rebuild it again. — ispiro, Aug 24 '15 at 23:26
@ispiro - if it can't find `BasePage` then you can't go to definition. Either way I tried cleaning, but that didn't have any effect. — Abe Miessler, Aug 24 '15 at 23:30
Here's another idea - according to [this question's](http://stackoverflow.com/questions/4764978/the-type-or-namespace-name-could-not-be-found) answers - that error might arise from targeting the wrong .net version. — ispiro, Aug 24 '15 at 23:33
`if it can't find BasePage then you can't go to definition` - Do you mean that you can't? But you _can_ see that file? Sounds like it _is_ a namespace issue - But you tried that - I guess I'm out of ideas. Good luck! — ispiro, Aug 24 '15 at 23:37
@ispiro - found the problem, take a look at my answer if you are interested. Thanks for trying! — Abe Miessler, Aug 24 '15 at 23:42

score 2 · Accepted Answer · answered Aug 24 '15 at 23:41

Ok - it looks like I needed to do a "Convert to Web Application" on the entire project in order to get my base class recognized. A lot of the older instructions that I've seen say to right click on the project and click "Convert to Web Applicaiton", but that was not an option using Visual Studio 2013. I had to:

Select the project I wanted to convert
In the top menu items I had to select Project -> Convert to Web Application

Once I did that, it changed my App_Code folder to Old_App_Code and then the base class was recognized everywhere. I didn't need to add namespaces or anything.

Hope this helps someone!

+1. From looking around a bit, it looks like maybe the files in App_code are marked with the wrong Build Action for a web application. (Just read quickly. I might be wrong.) — ispiro, Aug 24 '15 at 23:49

score 0 · Answer 2 · answered Aug 24 '15 at 23:05

0

Try adding a using statement at the beginning, like the using System.Web line.

maybe try the following:

using App_Code.BaseClasses.BasePage; (NOTE: this may change depending on your file structure)

answered Aug 24 '15 at 23:05

fraser jordan

114
1
9

No dice - I also tried using intellisense to see if there were any possible candidates that might include that class, but there isn't anything. – Abe Miessler Aug 24 '15 at 23:09
Are your forms and base class all in the same project? Or separate projects under the same solution? – fraser jordan Aug 24 '15 at 23:12
All in the same project – Abe Miessler Aug 24 '15 at 23:12
Hmmmm, so you have tried adding a using directive, have you tried adding an assembly reference? It seems strange seeing as they are in the same project, are they under separate namespaces? – fraser jordan Aug 24 '15 at 23:21
Is it even possible for a project to add a reference to itself? Seems circular. – Abe Miessler Aug 24 '15 at 23:27
You're right. Theoretically if they're in the same namespace there shouldn't be any reason your code would not find the class – fraser jordan Aug 24 '15 at 23:30
Found the issue - take a look at my answer if you are interested. Thanks! – Abe Miessler Aug 24 '15 at 23:42
Oh man, I would've never thought of that. Good to know If I ever come across this problem though! – fraser jordan Aug 24 '15 at 23:47

Class could not be found?

2 Answers2