Multiplatform - 使用 Jetpack 组件（ViewModel、Navigation3）

一、概念

二、ViewModel

2.1 添加依赖

[versions] viewModel = "2.9.6" [libraries] jetbrains-viewModel = { module = "org.jetbrains.androidx.lifecycle:lifecycle-viewmodel-compose", version.ref = "viewModel" } //可选（解决桌面端对于默认调度器 Dispatchers.Main.immediate 可能不可用） kotlinx-coroutinesSwing = { module = "org.jetbrains.kotlinx:kotlinx-coroutines-swing", version.ref = "kotlinx-coroutines" }

2.2 使用

在非 JVM 平台上，无法通过类型反射实例化对象。因此在公共代码中，不能直接调用无参数的 viewModel() 函数，每次创建 ViewModel 实例时，至少需提供一个初始化器作为参数。

若仅提供初始化器，库会在底层创建默认工厂。但您也可以实现自己的工厂，并调用公共 viewModel(...) 函数中更显式的重载版本，这与 Jetpack Compose 中的使用方式一致。

@Composable fun Demo( viewModel: MyViewModel = viewModel { MyViewModel() } ) {...}

三、Navigation3

3.1 添加依赖

[versions] navigation3 = "1.0.0-alpha06" navigation3ViewModel = "2.10.0-alpha08" navigation3Adaptive = "1.3.0-alpha04" navigation3Browser = "0.2.0" [libraries] jetbrains-navigation3-ui = { module = "org.jetbrains.androidx.navigation3:navigation3-ui", version.ref = "navigation3" } jetbrains-navigation3-viewModel = { module = "org.jetbrains.androidx.lifecycle:lifecycle-viewmodel-navigation3", version.ref = "navigation3ViewModel" } //可选（自适应布局） jetbrains-navigation3-adaptive = { module = "org.jetbrains.compose.material3.adaptive:adaptive-navigation3", version.ref = "navigation3Adaptive" } //可选（回退支持web浏览器历史） jetbrains-navigation3-browser = { module = "com.github.terrakok:navigation3-browser", version.ref = "compose-multiplatform-navigation3-browser" }

3.2 使用

@Serializable private data object RouteA : NavKey @Serializable private data class RouteB(val id: String) : NavKey // Creates the required serializing configuration for open polymorphism private val config = SavedStateConfiguration { serializersModule = SerializersModule { polymorphic(NavKey::class) { subclass(RouteA::class, RouteA.serializer()) subclass(RouteB::class, RouteB.serializer()) } } } @Composable fun BasicDslActivity() { // Consumes the serializing configuration val backStack = rememberNavBackStack(config, RouteA) NavDisplay( backStack = backStack, //... ) }