Compose Multiplatform Patterns

affaan-m/ECC/pi/core/skills/compose-multiplatform-patterns

作者 affaan-mef648e01899ba3e8dc6371642deaaf64b4477775无许可证275K 个星标收录于 2026年10月9日更新于 2026年10月9日仓库4天前更新

Compose Multiplatform and Jetpack Compose patterns for KMP projects — state management, navigation, theming, performance, and platform-specific UI. Use when building Compose or Jetpack Compose UI, state, navigation, or theming in a KMP project.

仅含说明Software Development

AI 生成的概览

面向 KMP 项目的 Compose Multiplatform 与 Jetpack Compose UI 参考模式。

功能: 提供使用 Compose Multiplatform 和 Jetpack Compose 在 Android、iOS、桌面端和 Web 上构建共享 UI 的指导与代码模式。内容涵盖基于 ViewModel 与 StateFlow 的状态管理、类型安全导航、可组合项设计、平台特定的 expect/actual UI、性能优化以及 Material 3 主题。同时列出应避免的反模式。产出为说明与代码示例，而非文件或脚本。
适用场景: 在 Kotlin Multiplatform 项目中构建或审查 Compose 或 Jetpack Compose UI 时使用。适用于 UI 状态、导航、可复用可组合项、主题或重组性能相关的工作。
运行要求: 不附带脚本或工具，仅为说明文档。应用示例需具备包含 Compose、Compose Navigation 以及 Koin、Material 3 等相关库的 Kotlin Multiplatform 或 Android 项目。

Compose Multiplatform Patterns

Patterns for building shared UI across Android, iOS, Desktop, and Web using Compose Multiplatform and Jetpack Compose. Covers state management, navigation, theming, and performance.

When to Activate

Building Compose UI (Jetpack Compose or Compose Multiplatform)
Managing UI state with ViewModels and Compose state
Implementing navigation in KMP or Android projects
Designing reusable composables and design systems
Optimizing recomposition and rendering performance

State Management

ViewModel + Single State Object

Use a single data class for screen state. Expose it as StateFlow and collect in Compose:

kotlin

data class ItemListState(    val items: List<Item> = emptyList(),    val isLoading: Boolean = false,    val error: String? = null,    val searchQuery: String = "")
class ItemListViewModel(    private val getItems: GetItemsUseCase) : ViewModel() {    private val _state = MutableStateFlow(ItemListState())    val state: StateFlow<ItemListState> = _state.asStateFlow()
    fun onSearch(query: String) {        _state.update { it.copy(searchQuery = query) }        loadItems(query)    }
    private fun loadItems(query: String) {        viewModelScope.launch {            _state.update { it.copy(isLoading = true) }            getItems(query).fold(                onSuccess = { items -> _state.update { it.copy(items = items, isLoading = false) } },                onFailure = { e -> _state.update { it.copy(error = e.message, isLoading = false) } }            )        }    }}

data class ItemListState(    val items: List<Item> = emptyList(),    val isLoading: Boolean = false,    val error: String? = null,    val searchQuery: String = "")
class ItemListViewModel(    private val getItems: GetItemsUseCase) : ViewModel() {    private val _state = MutableStateFlow(ItemListState())    val state: StateFlow<ItemListState> = _state.asStateFlow()
    fun onSearch(query: String) {        _state.update { it.copy(searchQuery = query) }        loadItems(query)    }
    private fun loadItems(query: String) {        viewModelScope.launch {            _state.update { it.copy(isLoading = true) }            getItems(query).fold(                onSuccess = { items -> _state.update { it.copy(items = items, isLoading = false) } },                onFailure = { e -> _state.update { it.copy(error = e.message, isLoading = false) } }            )        }    }}

Collecting State in Compose

kotlin

@Composablefun ItemListScreen(viewModel: ItemListViewModel = koinViewModel()) {    val state by viewModel.state.collectAsStateWithLifecycle()
    ItemListContent(        state = state,        onSearch = viewModel::onSearch    )}
@Composableprivate fun ItemListContent(    state: ItemListState,    onSearch: (String) -> Unit) {    // Stateless composable — easy to preview and test}

@Composablefun ItemListScreen(viewModel: ItemListViewModel = koinViewModel()) {    val state by viewModel.state.collectAsStateWithLifecycle()
    ItemListContent(        state = state,        onSearch = viewModel::onSearch    )}
@Composableprivate fun ItemListContent(    state: ItemListState,    onSearch: (String) -> Unit) {    // Stateless composable — easy to preview and test}

Event Sink Pattern

For complex screens, use a sealed interface for events instead of multiple callback lambdas:

kotlin

sealed interface ItemListEvent {    data class Search(val query: String) : ItemListEvent    data class Delete(val itemId: String) : ItemListEvent    data object Refresh : ItemListEvent}
// In ViewModelfun onEvent(event: ItemListEvent) {    when (event) {        is ItemListEvent.Search -> onSearch(event.query)        is ItemListEvent.Delete -> deleteItem(event.itemId)        is ItemListEvent.Refresh -> loadItems(_state.value.searchQuery)    }}
// In Composable — single lambda instead of manyItemListContent(    state = state,    onEvent = viewModel::onEvent)

sealed interface ItemListEvent {    data class Search(val query: String) : ItemListEvent    data class Delete(val itemId: String) : ItemListEvent    data object Refresh : ItemListEvent}
// In ViewModelfun onEvent(event: ItemListEvent) {    when (event) {        is ItemListEvent.Search -> onSearch(event.query)        is ItemListEvent.Delete -> deleteItem(event.itemId)        is ItemListEvent.Refresh -> loadItems(_state.value.searchQuery)    }}
// In Composable — single lambda instead of manyItemListContent(    state = state,    onEvent = viewModel::onEvent)

Navigation

Type-Safe Navigation (Compose Navigation 2.8+)

Define routes as @Serializable objects:

kotlin

@Serializable data object HomeRoute@Serializable data class DetailRoute(val id: String)@Serializable data object SettingsRoute
@Composablefun AppNavHost(navController: NavHostController = rememberNavController()) {    NavHost(navController, startDestination = HomeRoute) {        composable<HomeRoute> {            HomeScreen(onNavigateToDetail = { id -> navController.navigate(DetailRoute(id)) })        }        composable<DetailRoute> { backStackEntry ->            val route = backStackEntry.toRoute<DetailRoute>()            DetailScreen(id = route.id)        }        composable<SettingsRoute> { SettingsScreen() }    }}

@Serializable data object HomeRoute@Serializable data class DetailRoute(val id: String)@Serializable data object SettingsRoute
@Composablefun AppNavHost(navController: NavHostController = rememberNavController()) {    NavHost(navController, startDestination = HomeRoute) {        composable<HomeRoute> {            HomeScreen(onNavigateToDetail = { id -> navController.navigate(DetailRoute(id)) })        }        composable<DetailRoute> { backStackEntry ->            val route = backStackEntry.toRoute<DetailRoute>()            DetailScreen(id = route.id)        }        composable<SettingsRoute> { SettingsScreen() }    }}

Dialog and Bottom Sheet Navigation

Use dialog() and overlay patterns instead of imperative show/hide:

kotlin

NavHost(navController, startDestination = HomeRoute) {    composable<HomeRoute> { /* ... */ }    dialog<ConfirmDeleteRoute> { backStackEntry ->        val route = backStackEntry.toRoute<ConfirmDeleteRoute>()        ConfirmDeleteDialog(            itemId = route.itemId,            onConfirm = { navController.popBackStack() },            onDismiss = { navController.popBackStack() }        )    }}

NavHost(navController, startDestination = HomeRoute) {    composable<HomeRoute> { /* ... */ }    dialog<ConfirmDeleteRoute> { backStackEntry ->        val route = backStackEntry.toRoute<ConfirmDeleteRoute>()        ConfirmDeleteDialog(            itemId = route.itemId,            onConfirm = { navController.popBackStack() },            onDismiss = { navController.popBackStack() }        )    }}

Composable Design

Slot-Based APIs

Design composables with slot parameters for flexibility:

kotlin

@Composablefun AppCard(    modifier: Modifier = Modifier,    header: @Composable () -> Unit = {},    content: @Composable ColumnScope.() -> Unit,    actions: @Composable RowScope.() -> Unit = {}) {    Card(modifier = modifier) {        Column {            header()            Column(content = content)            Row(horizontalArrangement = Arrangement.End, content = actions)        }    }}

@Composablefun AppCard(    modifier: Modifier = Modifier,    header: @Composable () -> Unit = {},    content: @Composable ColumnScope.() -> Unit,    actions: @Composable RowScope.() -> Unit = {}) {    Card(modifier = modifier) {        Column {            header()            Column(content = content)            Row(horizontalArrangement = Arrangement.End, content = actions)        }    }}

Modifier Ordering

Modifier order matters — apply in this sequence:

kotlin

Text(    text = "Hello",    modifier = Modifier        .padding(16.dp)          // 1. Layout (padding, size)        .clip(RoundedCornerShape(8.dp))  // 2. Shape        .background(Color.White) // 3. Drawing (background, border)        .clickable { }           // 4. Interaction)

Text(    text = "Hello",    modifier = Modifier        .padding(16.dp)          // 1. Layout (padding, size)        .clip(RoundedCornerShape(8.dp))  // 2. Shape        .background(Color.White) // 3. Drawing (background, border)        .clickable { }           // 4. Interaction)

KMP Platform-Specific UI

expect/actual for Platform Composables

kotlin

// commonMain@Composableexpect fun PlatformStatusBar(darkIcons: Boolean)
// androidMain@Composableactual fun PlatformStatusBar(darkIcons: Boolean) {    val systemUiController = rememberSystemUiController()    SideEffect { systemUiController.setStatusBarColor(Color.Transparent, darkIcons) }}
// iosMain@Composableactual fun PlatformStatusBar(darkIcons: Boolean) {    // iOS handles this via UIKit interop or Info.plist}

// commonMain@Composableexpect fun PlatformStatusBar(darkIcons: Boolean)
// androidMain@Composableactual fun PlatformStatusBar(darkIcons: Boolean) {    val systemUiController = rememberSystemUiController()    SideEffect { systemUiController.setStatusBarColor(Color.Transparent, darkIcons) }}
// iosMain@Composableactual fun PlatformStatusBar(darkIcons: Boolean) {    // iOS handles this via UIKit interop or Info.plist}

Performance

Stable Types for Skippable Recomposition

Mark classes as @Stable or @Immutable when all properties are stable:

kotlin

@Immutabledata class ItemUiModel(    val id: String,    val title: String,    val description: String,    val progress: Float)

@Immutabledata class ItemUiModel(    val id: String,    val title: String,    val description: String,    val progress: Float)

Use `key()` and Lazy Lists Correctly

kotlin

LazyColumn {    items(        items = items,        key = { it.id }  // Stable keys enable item reuse and animations    ) { item ->        ItemRow(item = item)    }}

LazyColumn {    items(        items = items,        key = { it.id }  // Stable keys enable item reuse and animations    ) { item ->        ItemRow(item = item)    }}

Defer Reads with `derivedStateOf`

kotlin

val listState = rememberLazyListState()val showScrollToTop by remember {    derivedStateOf { listState.firstVisibleItemIndex > 5 }}

val listState = rememberLazyListState()val showScrollToTop by remember {    derivedStateOf { listState.firstVisibleItemIndex > 5 }}

Avoid Allocations in Recomposition

kotlin

// BAD — new lambda and list every recompositionitems.filter { it.isActive }.forEach { ActiveItem(it, onClick = { handle(it) }) }
// GOOD — key each item so callbacks stay attached to the right rowval activeItems = remember(items) { items.filter { it.isActive } }activeItems.forEach { item ->    key(item.id) {        ActiveItem(item, onClick = { handle(item) })    }}

// BAD — new lambda and list every recompositionitems.filter { it.isActive }.forEach { ActiveItem(it, onClick = { handle(it) }) }
// GOOD — key each item so callbacks stay attached to the right rowval activeItems = remember(items) { items.filter { it.isActive } }activeItems.forEach { item ->    key(item.id) {        ActiveItem(item, onClick = { handle(item) })    }}

Theming

Material 3 Dynamic Theming

kotlin

@Composablefun AppTheme(    darkTheme: Boolean = isSystemInDarkTheme(),    dynamicColor: Boolean = true,    content: @Composable () -> Unit) {    val colorScheme = when {        dynamicColor && Build.VERSION.SDK_INT >= Build.VERSION_CODES.S -> {            if (darkTheme) dynamicDarkColorScheme(LocalContext.current)            else dynamicLightColorScheme(LocalContext.current)        }        darkTheme -> darkColorScheme()        else -> lightColorScheme()    }
    MaterialTheme(colorScheme = colorScheme, content = content)}

@Composablefun AppTheme(    darkTheme: Boolean = isSystemInDarkTheme(),    dynamicColor: Boolean = true,    content: @Composable () -> Unit) {    val colorScheme = when {        dynamicColor && Build.VERSION.SDK_INT >= Build.VERSION_CODES.S -> {            if (darkTheme) dynamicDarkColorScheme(LocalContext.current)            else dynamicLightColorScheme(LocalContext.current)        }        darkTheme -> darkColorScheme()        else -> lightColorScheme()    }
    MaterialTheme(colorScheme = colorScheme, content = content)}

Anti-Patterns to Avoid

Using mutableStateOf in ViewModels when MutableStateFlow with collectAsStateWithLifecycle is safer for lifecycle
Passing NavController deep into composables — pass lambda callbacks instead
Heavy computation inside @Composable functions — move to ViewModel or remember {}
Using LaunchedEffect(Unit) as a substitute for ViewModel init — it re-runs on configuration change in some setups
Creating new object instances in composable parameters — causes unnecessary recomposition

References

See skill: android-clean-architecture for module structure and layering. See skill: kotlin-coroutines-flows for coroutine and Flow patterns.

来源与署名

来源：affaan-m/ECC位于pi/core/skills/compose-multiplatform-patterns提交ef648e0

许可证：无许可证

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Compose Multiplatform Patterns

Compose Multiplatform Patterns

When to Activate

State Management

ViewModel + Single State Object

Collecting State in Compose

Event Sink Pattern

Navigation

Type-Safe Navigation (Compose Navigation 2.8+)

Dialog and Bottom Sheet Navigation

Composable Design

Slot-Based APIs

Modifier Ordering

KMP Platform-Specific UI

expect/actual for Platform Composables

Performance

Stable Types for Skippable Recomposition

Use `key()` and Lazy Lists Correctly

Defer Reads with `derivedStateOf`

Avoid Allocations in Recomposition

Theming

Material 3 Dynamic Theming

Anti-Patterns to Avoid

References

来源与署名

更多来自 affaan-m/ECC 的技能

Unified Notifications Ops

Verification Loop

Ui To Vue

Unified Memory

Visa Doc Translate

Team Builder

更多Software Development技能

Playground

M5 Onboard

Cardputer Buddy

Web Design Guidelines

Vercel React Native Skills

Vercel React Best Practices

Compose Multiplatform Patterns

Compose Multiplatform Patterns

When to Activate

State Management

ViewModel + Single State Object

Collecting State in Compose

Event Sink Pattern

Navigation

Type-Safe Navigation (Compose Navigation 2.8+)

Dialog and Bottom Sheet Navigation

Composable Design

Slot-Based APIs

Modifier Ordering

KMP Platform-Specific UI

expect/actual for Platform Composables

Performance

Stable Types for Skippable Recomposition

Use key() and Lazy Lists Correctly

Defer Reads with derivedStateOf

Avoid Allocations in Recomposition

Theming

Material 3 Dynamic Theming

Anti-Patterns to Avoid

References

来源与署名

更多来自 affaan-m/ECC 的技能

Unified Notifications Ops

Verification Loop

Ui To Vue

Unified Memory

Visa Doc Translate

Team Builder

更多Software Development技能

Playground

M5 Onboard

Cardputer Buddy

Web Design Guidelines

Vercel React Native Skills

Vercel React Best Practices

Use `key()` and Lazy Lists Correctly

Defer Reads with `derivedStateOf`