expect/actual สำหรับข้อมูลอุปกรณ์

Sometimes you skip an interface and use expect/actual directly. It declares device info once in commonMain and implements it per platform.

In commonMain, write an expect class with the device facts you need. There is no body yet, only the shape both platforms must satisfy.

In androidMain, the actual reads Build.MODEL and the OS release to fill in real Android values at runtime.

In iosMain, the actual uses UIDevice to report Apple's model name and the running iOS version.

Every property on each actual must match the expect by name and type. A single mismatch and the compiler refuses to link the targets.

Common code creates DeviceInfo() and reads its properties like normal Kotlin. The correct actual is wired in at build time per target.

When the Android app builds, the androidMain actual is linked, so model returns the real hardware name from the Build class.

The identical call inside the iOS framework returns Apple's values, because the iosMain actual was compiled into that target instead.

Build lives in androidMain and UIDevice in iosMain. CommonMain never imports a platform type, which is exactly what keeps it shared.

An interface needs you to inject an implementation. expect/actual links automatically at compile time, so callers just construct the class.

For a single, stateless platform fact, expect/actual is the leaner choice. Reach for an interface when you also want to swap fakes freely.

Consider how the right device values reach each app.

You declared an expect DeviceInfo in commonMain and gave Android and iOS actuals, with matching signatures so each app reports its own values. 🎉