Question

hi i am having a different projects in my solution in the initial project (default project) i am accessing the global reference to App.xaml.cs in this way :-

App objref = (App)Application.Current;

But now i have added new project to my solution and trying to access the app.xaml.cs in the same way as defined earlier but i am not able to access app.xaml.cs ?

1)can i know the reason

2)What should i do if i want to use it in both the projects ?

Please let me know

Thanks in advance.

Answer 1

You can access it, but the new project will not be familiar with the derived App class that is in your project. To explain further we need to take inheritance into consideration.

There’s a generic definition for the Application class that exposes a number of predefined methods. Your App.xaml.cs is a new class definition that is derived from the Application class. It has the methods it inherited plus what ever methods and properties that you’ve added. To make use of these any code that is seeking to use your extra properties or methods must have access to the class definition. Your classes in the other projects that you’ve added do not have access to this definition.

You’ll need to make a class or interface definition that both projects have access to. There are several ways of organizing this. I’ll present one.

1. Create your main project in the solution. This contains your
   App.xaml.cs.
2. Create your class library project that contains the
   other code.
3. Create a third project called Common that only contains
   an Interface definition.
4. On the Interface definition define all of the methods/properties
   that you want both your class library and main project to have
   access too.
5. Have App.Xaml.cs implement this interface.
6. In the Class Library access var appReference =
   (IMyInterfaceName)Applcation.Current. You’ll have access to the
   methods that were defined in the interface