Kotlin Multiplatform Academy · 课时

在 Android 和 iOS 中收集 Flow

安全地将 Flow 接入 Compose 和 Swift

在 Android 和 iOS 中收集 Flow 是 CoddyKit 上的免费 Kotlin Multiplatform Academy 课时。这是第 4 节课，共 4 节。你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。这是 Kotlin Multiplatform Academy 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 Kotlin Multiplatform Academy 课程共包含 4 节课。

本课时的部分内容尚未翻译，以英文显示。

Two Apps, One Stream

Your shared code exposes a Flow, but each platform consumes it differently. The trick is collecting that one stream natively on Android and on iOS.

Compose Loves Flow

On Android, Jetpack Compose turns a Flow into state with collectAsState. Your composable redraws automatically whenever a new value arrives.

val state by viewModel.uiState
    .collectAsState()

Respect the Lifecycle

Prefer collectAsStateWithLifecycle so collection pauses when the screen is in the background. It saves battery and avoids needless work.

val state by viewModel.uiState
    .collectAsStateWithLifecycle()

Swift Cannot See suspend

Plain Flow does not bridge to Swift, because collect is a suspend call. Swift needs a callback-friendly wrapper instead.

Wrap Flow for iOS

A common fix is a small wrapper that subscribes and returns a cancel handle. iOS calls a closure on each value and stops when done.

fun watch(
    onEach: (UiState) -> Unit
): Closeable

Use a CoroutineScope

The wrapper launches collection inside a CoroutineScope it owns. Closing the handle cancels that scope so nothing leaks after the screen is gone.

SwiftUI Subscribes

From SwiftUI you call the wrapper in onAppear, push each value into an ObservableObject, and cancel in onDisappear.

SKIE Smooths the Bridge

Tools like SKIE generate Swift-friendly Flow APIs for you, so iOS devs collect with native async sequences and skip hand-written wrappers.

Always Cancel

However you bridge, make sure collection cancels when the screen disappears. An orphaned collector keeps running and quietly wastes resources.

Logic Stays Shared

Notice the pattern: only the thin collection layer is per platform. The data, operators, and state all stay in shared code where they belong. 🤝

Same Data, Native Feel

Both apps now react to the identical stream, yet each uses its native UI toolkit. That balance is exactly what KMP is built for.

Quick Check

Think about why iOS needs extra help.

Recap

You collected one shared stream two ways: Compose with collectAsStateWithLifecycle, and SwiftUI through a wrapper or SKIE. Shared logic, native UI. 🤝

常见问题解答

「在 Android 和 iOS 中收集 Flow」课时是免费的吗？

是的 — 「在 Android 和 iOS 中收集 Flow」的完整文本可在网页上免费阅读。要进行交互式练习（内置代码编辑器和全天候 AI 导师）并解锁 Kotlin Multiplatform Academy 课程的其余内容，请升级到 CoddyKit PRO。 Kotlin Multiplatform Academy 课程共包含 4 节课。

「在 Android 和 iOS 中收集 Flow」这节课中我会学到什么？

安全地将 Flow 接入 Compose 和 Swift 你通过在浏览器中直接运行的动手代码来练习 Kotlin Multiplatform Academy，全天候 AI 导师会在你学习这节课的过程中回答你的问题。

学习 Kotlin Multiplatform Academy 需要有经验吗？

无需任何先前经验。CoddyKit 上的 Kotlin Multiplatform Academy 课程适合初学者到高级学习者，你可以从这里开始或从头开始，按照自己的节奏学习。这是第 4 节课，共 4 节。

「在 Android 和 iOS 中收集 Flow」课时需要多长时间？

大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动，所以你能稳步进步，并在网页和应用中从离开的地方继续。

我能在这节 Kotlin Multiplatform Academy 课中编写并运行代码吗？

能。每节 Kotlin Multiplatform Academy 课都包含内置代码编辑器，你可以在浏览器中直接编写并运行真实代码，并获得即时 AI 反馈 — 无需本地设置。

此课程中的所有课时

← 返回 Kotlin Multiplatform Academy