Visual Studio: "This document is opened by another project" - wpf

Question

I spend most of my time developing controls for both WPF and Silverlight using the same codebase. To do this I add existing files from one project (say Silverlight) "as links" to the other (say WPF). For minor differences I use preprocessor directives like
#if SILVERLIGHT
...
#else
...
#endif
The code in these blocks is grayed out depending on the type of project you've opened the file from. So if you open your file from Silverlight project (where SILVERLIGHT is defined) the else part is gray and Intellisense doesn't work in it.
In order for WPF part to be processed by IDE (with coloring and Intellisense support) you need to open the file from the WPF project. When you try to do that you get a message box saying that "This document is opened by another project" and when you click OK it displays that file in the context of the Silverlight project (not what I wanted to see). So I have to close the file, navigate to WPF project again and open the file again. This is very, very annoying.
So the question is this: is there some sort of setting or add-on that would make Visual Studio reopen the file from the project where I double-clicked on it instead of showing that stupid message box and showing me that file from the "wrong" project?

Answer 1

This has happened to me about twice in a month now, not in a WPF application. No idea why it happens but in both cases the fix was to Clean the solution, reboot the PC (not just restart Visual Studio) and then build the solution.

Answer 2

You could make this a little easier to work with by using partial classes and multiple files: shared code that is the same for both WPF and Silverlight in a shared linked file, and a separate file for each containing the code specific to one or the other (with identical method/property signatures), each of which is only in one of the projects. Doing this allows both the WPF and Silverlight versions to be opened at once (since they're separate files) at the cost of adding a bunch of extra file management overhead.
Beyond that, get some extra memory and use separate solutions.

Answer 3

It occurred to me, when I had one project containing a linked file of other project under one VS solution. When I tried to navigate to the definition of a method in linked file, VS prompted with a message that this document is opened by another project.
To resolve this, I had to unload the project that owns the original file from the VS solution. After that navigating to method definition in normal time and debug time was not an issue.

Answer 4

Yes this is possible using Visual Studio Shell.
First instantiate EnvDTE80.DTE2 object:
private static EnvDTE80.DTE2 _dte;
public static EnvDTE80.DTE2 DTE
{
get
{
if (_dte == null)
_dte = ServiceProvider.GlobalProvider.GetService(typeof(DTE)) as DTE2;
return _dte;
}
}
and then:
// On Document Opening, close the existing instances.
// This event occurs when you double-click file in Solution Explorer.
DTE.Events.DocumentEvents.DocumentOpening += (s, e) =>
{
if(!DTE.ItemOperations.IsFileOpen(YOURFILENAME))
return;
foreach(Window win in DTE.Documents.Cast<Document>()
.FirstOrDefault(s => s.FullName == YOURFILENAME).Windows))
win.Close();
}
// next; VS itself will call DTE.ItemOperatins.OpenFile(YOURFILENAME);
HTH.