android - backStack 到 jetpack compose 界面时再次调用 api

Question

我在 View 模型 init 中调用 API。当我导航到另一个屏幕并返回到上一个屏幕时，我想再次调用 API clientInfoOnEvent() 来更新数据，但我可以在 Jetpack Compose 中执行此操作。我该怎么做？

Viewwmodel 代码:

@HiltViewModel
class ProfileViewModel @Inject constructor(
    private val profileUseCases: ProfileUseCases,
    private val clientNavigator: ClientNavigator,
    private val isLoggedInDataStore: IsLoggedInDataStore
) :
    ViewModel(), ClientNavigator by clientNavigator {

    private val _state = mutableStateOf(ProfileState())
    val state: State<ProfileState> = _state

    init {
        clientInfoOnEvent()
    }

    fun clientInfoOnEvent() {
        profileUseCases.getClientInfoUseCase().onEach { result ->
            when (result) {
                is Resource.Success -> {
                    _state.value = state.value.copy(info = result.data)
                }
                is Resource.Error -> {
                    _state.value =
                        state.value.copy(error = result.message ?: "An unexpected error occurred")
                }
                is Resource.Loading -> {
                    _state.value = state.value.copy(isLoading = true)
                }
            }
        }.launchIn(viewModelScope)
    }

}

屏幕代码:

val state = viewModel.state.value

Column(
    modifier = modifier.fillMaxWidth(),
    verticalArrangement = Arrangement.Center,
    horizontalAlignment = Alignment.Start
) {
    state.info?.apply {
        Text(
            text = "$givenName $lastName",
            style = AppFont.PoppinsTypography.button,
            color = AppColor.neutralColor.CHARCOAL,
            modifier = modifier.padding(top = 4.dp, bottom = 4.dp)
        )
        val clientData = let {
            it.copy(currency = Currency().copy(signSvg = it.currency?.signSvg.urlEncoder()))
        }
        TextIcon(
            text = stringResource(R.string.edit_profile),
            icon = painterResource(id = R.drawable.ic_right),
            color = AppColor.neutralColor.SPANISH_GRAY,
            style = AppFont.PoppinsTypography.caption,
            onCLick = {
                state.info?.let {
                    viewModel.navigate(
                        EditProfileDestination.createEditProfileRoute(
                            Gson().toJson(
                                clientData
                            )
                        )
                    )
                }
            })
    }
} 

Answer 1

您可以使用 LaunchedEffect : 当 View 出现时它会调用一次。

val state = viewModel.state.value
LaunchedEffect(Unit) {
    viewModel.clientInfoOnEvent()
}

您可以从 init 中删除此调用，以防止在第一次出现时重复调用。在 documentation 中查看有关 Compose 副作用的更多信息.