This is a boilerplate solution using the onion architecture for Xamarin.iOS and Xamarin.Android mobile projects.

The solution is separated into 3 main categories:

1. Core - Includes core models and interfaces as well as business logic.
2. Presentation - Includes iOS and Android project types.
3. Testing - Includes testing projects across for core and presentation projects.

• Includes:
  • Interfaces used throughout all projects
  • Concrete implementation of most entities (e.g. DTOs, models)
  • Shared enumerations

Contains web service implementations (e.g. REST APIs)

Implementation of local Realm database access.

• Includes:
  • Concrete implementations of Realm entities. Implementing entity interfaces from Mobile.Core.
  • Implementation of CRUD operations from service interfaces defined in Mobile.Core.

Uses MVVMCross to manage view models that are bound to views in native UI projects (e.g. iOS, Android). The properties defined in a view model are bound to properties on UI controls. The view models make calls to Mobile.Services.Http and Mobile.Services.Realm as needed. The view models can also take on the responsibility of navigation and common UI tasks (alert modals and process dialogs).

UI implementation of the app for iOS devices. MVVMCross view models are bound to view controllers. Each view controller then binds UI controls to properties from the bound view model.

• Includes:
  • ViewController - A view controller represents a "screen" in the app. Each screen is broken into 3 partial class files. The layout and presenter partial class files are nested under the view controller class file.
    • View Controller - Calls intitialize methods in presenter and layout files. Handles controller events (e.g. view did load, view did appear, etc...). Includes concrete implementations of view event handling. Example file name: MainViewController.cs
    • Presenter - Responsible for creating and configuring all of the views (controls) that the screen requires. Wires up view events and binds data to UI elements via MVVMCross. Example file name: MainViewController.presenter.cs
    • Layout - Responsible for positioning UI elements on the screen (via auto layout constraints). Exanple file name: MainViewController.layout.cs
  • Views - Any custom UI elements that the application requires are managed here (e.g. custom textbox input).

The UI implementation of the app for Android devices. MVVMCross view models are bound to activities/fragments based on name. For example if there is a view model named MainViewModel then the activity/fragment that you want to bind to it should be named MainView. Controls are bound to MVVMCross using the attribute local:MvxBind directly on views in layout (axml) files. For example you if you want to bind the Text property of a TextView to a property on a view model called Name you would add an attribute to the TextView like this: local:MvxBind="Text Name".

Includes SVG resources that are used in both iOS and Android presentation projects.

An iOS test runner application that executes the tests created in Mobile.ViewModels.Tests.Shared.

An Android test runner application that executes the tests created in Mobile.ViewModels.Tests.Shared.

Includes all ViewModel test implementations. It is referenced by the platform-specific test runner projects.

• ACR User Dialogs - A cross platform library that allows you to call for standard user dialogs from a shared/portable library.
• Automapper - Object mapper
• MVVMCross - Model View/View Model framework
• NUnit - Unit testing framework
• Realm - Mobile database
• Shouldly - Testing assertion framework
• XamSvg - Vector image support in iOS and Android

If you want to start your own app from the boilerplate solution follow the following steps to get up and running.

1. Create a project directory for your solution (or clone a git repo you've already created).
2. Clone the Xamarin-Architecture repo.
3. Copy all the folders and files (exluding the .git folder) from the Xamarin-Architecture folder to your project's root folder.
4. Rename Xamarin-Architecture.sln to match your desired namespace.
5. Rename project folders to match your namespace
   • 01-Core/Mobile.Core
   • 01-Core/Mobile.Services.Http
   • 01-Core/Mobile.Services.Realm
   • 01-Core/Mobile.ViewModels
   • 02-Presentation/Mobile.Android
   • 02-Presentation/Mobile.iOS
   • 02-Presentation/Mobile.Svg
   • 03-Tests/Mobile.ViewModels.Tests.Android
   • 03-Tests/Mobile.ViewModels.Tests.iOS
   • 03-Tests/Mobile.ViewModels.Tests.Shared
6. Rename project files (.csproj)
   • 01-Core/Mobile.Core/Mobile.Core.csproj
   • 01-Core/Mobile.Services.Http/Mobile.Services.Http.csproj
   • 01-Core/Mobile.Services.Realm/Mobile.Services.Realm.csproj
   • 01-Core/Mobile.ViewModels/Mobile.ViewModels.csproj
   • 02-Presentation//Mobile.Android/Mobile.Android.csproj
   • 02-Presentation/Mobile.iOS/Mobile.iOS.csproj
   • 02-Presentation/Mobile.Svg/Mobile.Svg.csproj
   • 03-Tests/Mobile.ViewModels.Tests.Android/Mobile.ViewModels.Tests.Android.csproj
   • 03-Tests/Mobile.ViewModels.Tests.iOS/Mobile.ViewModels.Tests.iOS.csproj
   • 03-Tests/Mobile.ViewModels.Tests.Shared/Mobile.ViewModels.Tests.Shared.shproj
   • 03-Tests/Mobile.ViewModels.Tests.Shared/Mobile.ViewModels.Tests.Shared.projitems
7. Edit all of the project files in a text editor and update:
   • The root namespace: <RootNamespace></RootNamespace>
   • The assembly name: <AssemblyName></AssemblyName>
   • Project references (when applicable): <ProjectReference></ProjectReference>
8. Edit all the project paths in the solution file (.sln).
9. Open the solution in Visual Studio.
10. Edit the info.plist file in the iOS presentation project.
    • Change the Application Name
    • Change the Bundle Identifier
11. Change the value for the <string name="app_name"></string> element in the Strings.xml file in the Android presentation project (located at Resources/values).
12. Open the AndroidManifest.xml file in the Android presentation project and change the value for Package name.
13. Repeat step 10 for the iOS test runner project.
14. Repeat steps 11 and 12 for the Android test runner project.
15. Update the namespaces for all classes in all projects. Note: This can be made simpler by doing a find and replace in all solution files. For example you can do a find on "namespace Mobile.Core.", and replace with 'namespace [YourNameSpace].Core.". OR if you're just prepending a value to the root namespace you can do a find on "namespace Mobile." and replace with "namespace YouNameSpace.Mobile.".
16. Update all the using statements in all classes in all projects. Note: This can be made simpler by doing a find and replace in all solution files. For example you can do a find on "using Mobile.Core.", and replace with 'using [YourNameSpace].Core.". OR if you're just prepending a value to the root namespace you can do a find on "using Mobile." and replace with "using YouNameSpace.Mobile.".
17. Open the App.cs file in the ViewModels core project and change .InNamespace("Mobile.Services.Realm") to reflect the correct namespace.
18. Rebuild the solution & address any issues.
19. Run the presentation and test projects to make sure everything loads properly.