Kotlin Multiplatform Mobile (KMM) development has gained significant popularity in recent years due to its ability to share code between different platforms, such as Android and iOS. This allows developers to write their application logic once and use it across multiple platforms, reducing time and effort in development.
Introduction to KMM
KMM is an extension of Kotlin Native, a technology that enables the compilation of Kotlin code to native binaries, allowing it to run directly on the target platform without the need for a virtual machine or an interpreter. This makes it possible to share code between different platforms.
KMM provides a set of libraries and tools that allow developers to write shared code using Kotlin. This shared code can then be used by both the Android and iOS versions of the application, reducing the need to duplicate code and speeding up development.
Code Structure in KMM
In KMM, the code is organized into three main modules: shared, android, and ios. The shared module contains the business logic and data models of the application, while the android and ios modules contain platform-specific implementations of the user interface and other platform-specific features.
The shared code in the shared module can be accessed by both the android and ios modules through the use of shared interfaces and actual implementations. This allows developers to write platform-specific code only when necessary and use the shared code as much as possible.
Code Sharing Techniques
KMM provides several techniques for code sharing, including:
Shared Interfaces
Shared interfaces define the contract for platform-independent code that can be implemented differently for Android and iOS. For example, a shared interface for fetching data from a remote server can have separate implementations for Android and iOS, depending on the platform-specific networking libraries.
Expect-Actual Declarations
Expect-actual declarations allow developers to define platform-specific behavior in the shared code. The expect keyword is used to define the expected behavior, while the actual keyword is used to provide the platform-specific implementation.
For example, an expect-actual declaration can be used to define a platform-specific logger, where the expect declaration defines the contract for the logger, and the actual declaration provides the implementation using the logging library specific to each platform.
Code Sharing Best Practices
To maximize code sharing in KMM, it is recommended to follow these best practices:
- Identify and extract business logic and data models into the shared module.
- Use shared interfaces to define platform-independent functionality.
- Leverage expect-actual declarations to provide platform-specific implementations.
- Test shared code using unit tests that can be executed on both Android and iOS.
- Use platform-specific code only when necessary, and try to reuse shared code as much as possible.
Conclusion
Kotlin Multiplatform Mobile development provides a powerful platform for code sharing between Android and iOS applications. With KMM, developers can write their application logic once and use it across multiple platforms, reducing development time and effort.
By organizing the code into shared, android, and ios modules and using techniques like shared interfaces and expect-actual declarations, developers can maximize code sharing and reduce the need for code duplication.
KMM is a promising technology that simplifies the process of developing cross-platform applications and is rapidly gaining traction among developers. With its ability to share code, KMM helps improve code maintainability, reduce development effort, and ultimately deliver a better user experience across multiple platforms.
本文来自极简博客，作者：浅笑安然，转载请注明原文链接：Kotlin Multiplatform Mobile Development
