How do I add a XAML page to a Universal App?

Question

I created a new Blank App. Everything works as it should. Now I want to add a new page. This is the wrong way I'm doing it:
First, I add a new Blank Page to the Windows Project
foo.xml.cs
namespace testapp
/// <summary>
/// An empty page that can be used on its own or navigated to within a Frame.
/// </summary>
public sealed partial class foo : Page
public foo()
this.InitializeComponent();
Then I add the same class name to the Shared project
foo.cs
namespace ZUMOAPPNAME
class foo
I modify foo.cs to
namespace testapp
public sealed partial class foo
public void shared()
win();
And then add a method to foo.xaml.cs to make it
namespace testapp
/// <summary>
/// An empty page that can be used on its own or navigated to within a Frame.
/// </summary>
public sealed partial class foo : Page
public foo()
this.InitializeComponent();
public void win()
shared();
The win method can call the shared method.
However, for the shared method, the compiler gives me this error:
The name 'win' does not exist in the current context
What's the proper way to add a new page?

Answer 1

Hi Greg,
Take a look at my blog entry
Strategies for sharing code in XAML-based Universal apps
As Magnus notes, all parts of a partial class need to be in the same namespace to be part of the same class. ZUMOAPPNAME.foo and testapp.foo are unrelated classes.
It's not clear exactly what you're trying to do here, but a common pattern is to have different Xaml for the Windows and WindowsPhone projects but to share data. A good way to do that is to create the new page with the same name (for example: "foo")
in both the Windows and WindowsPhone projects. This will add a foo.xaml and foo.xaml.cs file in each and will define the foo class in both foo.xaml.cs files.
You can then add a foo.cs file in the shared project with your shared functions:
Shared/Foo.cs:
namespace testapp
public sealed partial class foo
public void shared()
do_shared_stuff();
do_plat_specific_stuff();
And call it from the platform specific functions:
Windows\foo.xaml.cs:
namespace testapp
/// <summary>
/// An empty page that can be used on its own or navigated to within a Frame.
/// </summary>
public sealed partial class foo : Page
public foo()
this.InitializeComponent();
shared();
public void do_platform_specific_stuff()
// do windows stuff
You can use this to mix and match as much as you'd like. If you have very straigtforward UI you may be able to copy the entire .Xaml and .Xaml.cs into the shared directory or you may have platform specific Xaml but share the Xaml.cs file. In most cases you'll
have a mix of platform specific xaml and code and shared code.