如何在jetpack compose中为自定义主题模式制作启动屏幕

Question

我已经实现了自定义主题模式而不是选择系统主题，现在我无法为我的自定义主题实现启动屏幕。 我想检查我的首选项中的值，然后将更改应用到splash api。

@Inject
lateinit var splashViewModel: SplashViewModel

@RequiresApi(Build.VERSION_CODES.S)
override fun onCreate(savedInstanceState: Bundle?) {
    installSplashScreen().setKeepOnScreenCondition {
        if (splashViewModel.isDarkMode.value){
        splashScreen.setSplashScreenTheme(R.style.SplashScreenTheme) }
        splashViewModel.isLoading.value
    }
    super.onCreate(savedInstanceState)
    setContent {
        val userViewModel: UserViewModel = viewModel()
        val isDarkTheme =  userViewModel.getSavedTheme().collectAsState(initial = true).value
        userViewModel.observeLifecycleEvents(LocalLifecycleOwner.current.lifecycle)
        SharpWalletTheme(darkTheme = isDarkTheme) {
            val startDestination by splashViewModel.startDestination
            val navController = rememberNavController()

            val isUserAuth by userViewModel.isUserAuth
            Surface(
                modifier = Modifier.fillMaxSize(), color = MaterialTheme.colors.background
            ) {
                RootNavigationGraph(
                    navHostController = navController,
                    startDestination = startDestination,
                    userViewModel = userViewModel,
                    toAuthUser = isUserAuth,
                )
            }
        }
    }
}

}

-更新1 我的splashViewModel如下-

class SplashViewModel @Inject constructor(
private val repository: UserRepository

) : ViewModel() {

private val _isLoading: MutableState<Boolean> = mutableStateOf(true)
val isLoading: State<Boolean> = _isLoading

private val _startDestination: MutableState<String> = mutableStateOf(Graph.ON_BOARDING)
val startDestination: State<String> = _startDestination

private val _isDarkMode: MutableState<Boolean> = mutableStateOf(true)
val isDarkMode: State<Boolean> = _isDarkMode

init {
    viewModelScope.launch {
        repository.readDarkModePreference().collect {
            _isDarkMode.value = it
        }
    }
    viewModelScope.launch {
        repository.readOnBoardingState().collect { completed ->
            if (completed) {
                _startDestination.value = Graph.MAIN
            } else {
                _startDestination.value = Graph.ON_BOARDING
            }
            delay(500)
            _isLoading.value = false
        }
    }
}

}

Answer 1

我认为您无法在显示后更改启动屏幕，您可以做的是快速从默认启动屏幕转换到与正确主题匹配的辅助“启动屏幕”。

@RequiresApi(Build.VERSION_CODES.S)
override fun onCreate(savedInstanceState: Bundle?) {
    val splashScreen = installSplashScreen()

    splashScreen.setOnExitAnimationListener { splashScreenProvider ->
        val fadeOut = ObjectAnimator.ofFloat(splashScreenProvider.view, View.ALPHA, 0f)
        fadeOut.duration = 500L // Or your desired duration
        fadeOut.doOnEnd { splashScreenProvider.remove() }
        fadeOut.start()
    }

    super.onCreate(savedInstanceState)
    
    splashViewModel.isDarkMode.observe(this, { isDarkMode ->
        if (isDarkMode) {
            // Here, instead of changing the splash screen (which you can't after it's shown),
            // You might transition to another screen or adjust the current theme, to mimic the splash screen 
            // adapting to the dark mode. 
        }
    })

    // Rest of your code...
}