My C# WinForms solution has two projects. A DLL which is the main project I'm working on, and an executable WinForms I call "Sandbox" so that I can compile/run/debug the DLL easily in one go.
I'm working in .Net 4.0 for both projects.
Everything was working fine until I added some seemingly innocent code, and a reference to System.Web in the DLL. Now my Sandbox project can't see the namespace of the DLL project. I didn't change anything which I believe should have affected this.
If I delete the project reference to the DLL from the Sandbox references and re-add it, then the red underlines all disappear and the colour coding comes back for all my classes etc; but as as soon as I try to build the solution, the whole thing falls apart again.
When I right-click the DLL project in the Sandbox's references and view in object browser, I can see the namespace and all the stuff in there.
I have a feeling this might be some sort of bug?
Is this some sort of VS2010 bug? I had this same issue a few months ago and I could only fix it at the time by making a whole new project and re-importing my files. This time, however, I have a bajillion files and will only do that as a last resort!
Edit: After panickedly going through and undoing all my changes, trying to find what caused the problems, it seems to be this line:
string url = "http://maps.google.com?q=" + HttpUtility.UrlEncode(address);
If I comment out this line, then I get no namespace errors and the project builds fine. I can't see anything wrong with this line though.