我是 android 初学者，也是 jetpack compose 的新手，我最近学习了使用 screenState 数据类和事件接口处理状态/事件，我想知道如何将它们与 compose 目的地一起使用
data class ScreenState(
val name: String = "",
val phoneNumber: String = ""
)
sealed interface ContactEvent {
data class nameTextField(val name: String): ContactEvent
data class phoneNumberTextField(val phoneNumber: String): ContactEvent
object saveName: ContactEvent
object savePhoneNumber: ContactEvent
data class navigateToPage(val nav: DestinationsNavigator): ContactEvent
}
@RootNavGraph(start = true)
@Destination
@Composable
fun Name(
nav: DestinationsNavigator,
state: ScreenState,
onEvent: (ContactEvent) -> Unit
) {
Scaffold {
Box(modifier = Modifier.padding(it)) {
Column {
TextField(
value = state.name,
onValueChange = { text ->
onEvent(ContactEvent.nameTextField(text))
}
)
Button(
onClick = {
onEvent(ContactEvent.saveName)
onEvent(ContactEvent.navigateToPage(nav))
}
) {
Text(text = "Name to DB")
}
}
}
}
}
这些按顺序排列：状态数据类、事件密封接口、我的撰写屏幕
我得到的错误是
致命异常：主要 进程：com.example.composedestinations，PID：5154 java.lang.RuntimeException：已请求 ScreenState，但它不存在
E FATAL EXCEPTION: main
Process: com.example.composedestinations, PID: 5154
java.lang.RuntimeException: ScreenState was requested, but it is not present
at com.ramcosta.composedestinations.navigation.DestinationDependenciesContainerImpl.require(DestinationDependenciesContainer.kt:124)
at com.example.composedestinations.Screens.destinations.NameDestination.Content(NameDestination.kt:48)
at com.ramcosta.composedestinations.spec.DestinationStyleKt.CallComposable(DestinationStyle.kt:274)
at com.ramcosta.composedestinations.spec.DestinationStyleKt.access$CallComposable(DestinationStyle.kt:1)
at com.ramcosta.composedestinations.spec.DestinationStyleKt$addActivityDestination$1.invoke(DestinationStyle.kt:163)
at com.ramcosta.composedestinations.spec.DestinationStyleKt$addActivityDestination$1.invoke(DestinationStyle.kt:162)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:139)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:35)
at androidx.navigation.compose.NavHostKt$NavHost$14$1.invoke(NavHost.kt:308)
at androidx.navigation.compose.NavHostKt$NavHost$14$1.invoke(NavHost.kt:306)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:109)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:35)
at androidx.compose.runtime.CompositionLocalKt.CompositionLocalProvider(CompositionLocal.kt:248)
at androidx.compose.runtime.saveable.SaveableStateHolderImpl.SaveableStateProvider(SaveableStateHolder.kt:84)
at androidx.navigation.compose.NavBackStackEntryProviderKt.SaveableStateProvider(NavBackStackEntryProvider.kt:65)
at androidx.navigation.compose.NavBackStackEntryProviderKt.access$SaveableStateProvider(NavBackStackEntryProvider.kt:1)
at androidx.navigation.compose.NavBackStackEntryProviderKt$LocalOwnersProvider$1.invoke(NavBackStackEntryProvider.kt:52)
at androidx.navigation.compose.NavBackStackEntryProviderKt$LocalOwnersProvider$1.invoke(NavBackStackEntryProvider.kt:51)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:109)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:35)
at androidx.compose.runtime.CompositionLocalKt.CompositionLocalProvider(CompositionLocal.kt:228)
at androidx.navigation.compose.NavBackStackEntryProviderKt.LocalOwnersProvider(NavBackStackEntryProvider.kt:47)
at androidx.navigation.compose.NavHostKt$NavHost$14.invoke(NavHost.kt:306)
at androidx.navigation.compose.NavHostKt$NavHost$14.invoke(NavHost.kt:295)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:139)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:35)
at androidx.compose.animation.AnimatedContentKt$AnimatedContent$6$1$5.invoke(AnimatedContent.kt:755)
at androidx.compose.animation.AnimatedContentKt$AnimatedContent$6$1$5.invoke(AnimatedContent.kt:744)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:118)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:35)
at androidx.compose.animation.AnimatedVisibilityKt.AnimatedEnterExitImpl(AnimatedVisibility.kt:818)
at androidx.compose.animation.AnimatedContentKt$AnimatedContent$6$1.invoke(AnimatedContent.kt:726)
at androidx.compose.animation.AnimatedContentKt$AnimatedContent$6$1.invoke(AnimatedContent.kt:709)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:109)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:35)
at androidx.compose.animation.AnimatedContentKt.AnimatedContent(AnimatedContent.kt:768)
at androidx.navigation.compose.NavHostKt.NavHost(NavHost.kt:273)
at androidx.navigation.compose.NavHostKt.NavHost(NavHost.kt:128)
at com.ramcosta.composedestinations.DefaultNavHostEngine.NavHost(DefaultNavHostEngine.kt:79)
2024-03-29 04:14:41.005 5154-5154 AndroidRuntime com.example.composedestinations E at com.ramcosta.composedestinations.DestinationsNavHostKt.DestinationsNavHost(DestinationsNavHost.kt:71)
at com.example.composedestinations.ComposableSingletons$MainActivityKt$lambda-1$1.invoke(MainActivity.kt:32)
at com.example.composedestinations.ComposableSingletons$MainActivityKt$lambda-1$1.invoke(MainActivity.kt:31)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:109)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:35)
at androidx.compose.material3.SurfaceKt$Surface$1.invoke(Surface.kt:132)
at androidx.compose.material3.SurfaceKt$Surface$1.invoke(Surface.kt:114)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:109)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:35)
at androidx.compose.runtime.CompositionLocalKt.CompositionLocalProvider(CompositionLocal.kt:228)
at androidx.compose.material3.SurfaceKt.Surface-T9BRK9s(Surface.kt:111)
at com.example.composedestinations.ComposableSingletons$MainActivityKt$lambda-2$1.invoke(MainActivity.kt:28)
at com.example.composedestinations.ComposableSingletons$MainActivityKt$lambda-2$1.invoke(MainActivity.kt:26)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:109)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:35)
at androidx.compose.runtime.CompositionLocalKt.CompositionLocalProvider(CompositionLocal.kt:228)
at androidx.compose.material3.TextKt.ProvideTextStyle(Text.kt:360)
at androidx.compose.material3.MaterialThemeKt$MaterialTheme$1.invoke(MaterialTheme.kt:81)
at androidx.compose.material3.MaterialThemeKt$MaterialTheme$1.invoke(MaterialTheme.kt:80)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:109)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:35)
at androidx.compose.runtime.CompositionLocalKt.CompositionLocalProvider(CompositionLocal.kt:228)
at androidx.compose.material3.MaterialThemeKt.MaterialTheme(MaterialTheme.kt:73)
at com.example.composedestinations.ui.theme.ThemeKt.ComposeDestinationsTheme(Theme.kt:65)
at com.example.composedestinations.ComposableSingletons$MainActivityKt$lambda-3$1.invoke(MainActivity.kt:26)
at com.example.composedestinations.ComposableSingletons$MainActivityKt$lambda-3$1.invoke(MainActivity.kt:25)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:109)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:35)
at androidx.compose.ui.platform.ComposeView.Content(ComposeView.android.kt:428)
at androidx.compose.ui.platform.AbstractComposeView$ensureCompositionCreated$1.invoke(ComposeView.android.kt:252)
at androidx.compose.ui.platform.AbstractComposeView$ensureCompositionCreated$1.invoke(ComposeView.android.kt:251)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:109)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:35)
at androidx.compose.runtime.CompositionLocalKt.CompositionLocalProvider(CompositionLocal.kt:228)
at androidx.compose.ui.platform.CompositionLocalsKt.ProvideCommonCompositionLocals(CompositionLocals.kt:186)
at androidx.compose.ui.platform.AndroidCompositionLocals_androidKt$ProvideAndroidCompositionLocals$3.invoke(AndroidCompositionLocals.android.kt:119)
at androidx.compose.ui.platform.AndroidCompositionLocals_androidKt$ProvideAndroidCompositionLocals$3.invoke(AndroidCompositionLocals.android.kt:118)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:109)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:35)
at androidx.compose.runtime.CompositionLocalKt.CompositionLocalProvider(CompositionLocal.kt:228)
2024-03-29 04:14:41.006 5154-5154 AndroidRuntime com.example.composedestinations E at androidx.compose.ui.platform.AndroidCompositionLocals_androidKt.ProvideAndroidCompositionLocals(AndroidCompositionLocals.android.kt:110)
at androidx.compose.ui.platform.WrappedComposition$setContent$1$1$2.invoke(Wrapper.android.kt:139)
at androidx.compose.ui.platform.WrappedComposition$setContent$1$1$2.invoke(Wrapper.android.kt:138)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:109)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:35)
at androidx.compose.runtime.CompositionLocalKt.CompositionLocalProvider(CompositionLocal.kt:248)
at androidx.compose.ui.platform.WrappedComposition$setContent$1$1.invoke(Wrapper.android.kt:138)
at androidx.compose.ui.platform.WrappedComposition$setContent$1$1.invoke(Wrapper.android.kt:123)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:109)
at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:35)
at androidx.compose.runtime.ActualJvm_jvmKt.invokeComposable(ActualJvm.jvm.kt:90)
at androidx.compose.runtime.ComposerImpl.doCompose(Composer.kt:3302)
at androidx.compose.runtime.ComposerImpl.composeContent$runtime_release(Composer.kt:3235)
at androidx.compose.runtime.CompositionImpl.composeContent(Composition.kt:723)
at androidx.compose.runtime.Recomposer.composeInitial$runtime_release(Recomposer.kt:1071)
at androidx.compose.runtime.CompositionImpl.composeInitial(Composition.kt:631)
at androidx.compose.runtime.CompositionImpl.setContent(Composition.kt:617)
at androidx.compose.ui.platform.WrappedComposition$setContent$1.invoke(Wrapper.android.kt:123)
at androidx.compose.ui.platform.WrappedComposition$setContent$1.invoke(Wrapper.android.kt:114)
at androidx.compose.ui.platform.AndroidComposeView.setOnViewTreeOwnersAvailable(AndroidComposeView.android.kt:1289)
at androidx.compose.ui.platform.WrappedComposition.setContent(Wrapper.android.kt:114)
at androidx.compose.ui.platform.WrappedComposition.onStateChanged(Wrapper.android.kt:164)
at androidx.lifecycle.LifecycleRegistry$ObserverWithState.dispatchEvent(LifecycleRegistry.kt:322)
at androidx.lifecycle.LifecycleRegistry.addObserver(LifecycleRegistry.kt:199)
at androidx.compose.ui.platform.WrappedComposition$setContent$1.invoke(Wrapper.android.kt:121)
at androidx.compose.ui.platform.WrappedComposition$setContent$1.invoke(Wrapper.android.kt:114)
at androidx.compose.ui.platform.AndroidComposeView.onAttachedToWindow(AndroidComposeView.android.kt:1364)
at android.view.View.dispatchAttachedToWindow(View.java:20479)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3489)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3496)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3496)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3496)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:3496)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2417)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1952)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:8171)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:972)
at android.view.Choreographer.doCallbacks(Choreographer.java:796)
at android.view.Choreographer.doFrame(Choreographer.java:731)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:957)
at android.os.Handler.handleCallback(Handler.java:938)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:223)
at android.app.ActivityThread.main(ActivityThread.java:7656)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
好吧，因为我是新手，所以我还没有真正尝试过任何东西
将您的 ScreenState 数据类标记为 Parcelable，我们不能直接将数据类作为参数发送。
将以下插件添加到各自的 gradle 文件中。
// project level gradle
plugins {
..
id("org.jetbrains.kotlin.android") version "1.9.0" apply false
}
//app level gradle
plugins {
..
id("kotlin-parcelize")
}
现在同步您的项目并将数据类标记为 Parcelable 类，如下所示，
@Parcelize
data class ScreenState(
val name: String = "",
val phoneNumber: String = ""
) : Parcelable