MvvmCross supports platform-specific code through several mechanisms, allowing developers to create cross-platform applications while still leveraging native platform features. Here's a detailed overview of how MvvmCross facilitates platform-specific code:
1. Separation of Concerns**
MvvmCross applications are typically structured into two main parts: a Core project and platform-specific UI projects. The Core project, often implemented as a Portable Class Library (PCL) or .NET Standard library, contains the business logic, models, view models, and interfaces for platform-specific services. This separation allows for maximum code reuse across platforms while keeping platform-specific code isolated in the UI projects[2][7].2. Inversion of Control (IoC) and Dependency Injection**
MvvmCross uses an IoC container to manage dependencies. This allows developers to register platform-specific services in the platform-specific projects and inject them into the Core project's view models. For example, if an application needs to access the camera, the Core project can define an interface for camera access, and each platform-specific project can provide its own implementation of this interface. The IoC container then resolves these dependencies at runtime, ensuring that the correct platform-specific service is used[2][8][11].3. Platform-Specific Services**
Platform-specific services are implemented in the native UI projects. These services are registered in the Setup class of each platform project. The Setup class is responsible for bootstrapping MvvmCross and registering platform-specific services with the IoC container. This allows view models in the Core project to use platform-specific functionality without directly referencing platform-specific APIs[2][7].4. Plugin Framework**
MvvmCross includes a plugin framework that allows developers to easily integrate platform-specific features into their applications. Plugins can provide functionalities like GPS location, localization, sensors, and more. These plugins are registered with the IoC container, enabling view models to access platform-specific features through dependency injection. This framework also supports mock implementations for testing purposes[4][11].5. Customizable Binding Engine**
MvvmCross provides a customizable binding engine that allows developers to create custom bindings for platform-specific views. This feature is particularly useful when working with native controls that do not support standard data binding mechanisms. By defining custom bindings, developers can ensure that their view models are properly connected to platform-specific views[4].6. Platform Presenters**
MvvmCross uses platform-specific presenters (e.g., `IMvxIosViewPresenter`, `IMvxAndroidViewPresenter`) to manage how views are displayed on each platform. These presenters allow for customization of the presentation logic, enabling developers to adapt the UI behavior to the specific platform's requirements[3].In summary, MvvmCross supports platform-specific code by providing a structured approach to separating business logic from platform-specific implementation, leveraging IoC and dependency injection for service management, and offering customizable binding and plugin frameworks for integrating native features. This allows developers to maximize code reuse while still delivering platform-specific user experiences.
Citations:[1] https://www.suneco.nl/blogs/boost-your-xamarin-native-projects-with-mvvmcross/
[2] https://dev.to/christian1006/creating-cross-platform-xamarin-applications-using-the-mvvmcross-framework-2920
[3] https://canbilgin.wordpress.com/tag/mvvmcross/
[4] https://github.com/MvvmCross/MvvmCross
[5] https://www.codeproject.com/Articles/863695/Introduction-to-Mvvmcross-Platform
[6] https://mentormate.com/blog/6-reasons-mvvmcross-speeds-xamarin-development-personalizes-ux/
[7] https://www.mvvmcross.com/documentation/getting-started/mvvmcross-overview
[8] https://stackoverflow.com/questions/14337063/platform-specific-ioc-in-mvvmcross
[9] https://www.mvvmcross.com/documentation/getting-started/getting-started
[10] https://leaware.com/creating-cross-platform-xamarin-applications-using-the-mvvmcross-framework/
[11] https://learn.microsoft.com/en-us/archive/msdn-magazine/2014/august/windows-phone-build-mvvm-apps-with-xamarin-and-mvvmcross