函数在jetpack compose中暴露loadState时多次重组

Question

我是jetpack撰写的新手，并试图实现他们新的分页撰写api。我面临的问题是，如果我暴露loadState来检查列表是否正在加载我的功能重组多次，如果我删除加载状态侦听器，那么它就会按预期工作。在下面的代码中，我编写了整个可组合函数

private fun SupportScreen() {
val issueTypes =
produceState<ApiResource<IssueModel>>(initialValue = ApiResource.loading()) {
value = supportViewModel.getIssuesType()
}.value
when (issueTypes.status) {
ApiResource.Status.SUCCESS -> {
dashboardActivity.stopProgressBar()
val getTickets = remember { supportViewModel.getAllTickets() }
val tickets = getTickets.collectAsLazyPagingItems()
LaunchedEffect(tickets.loadState) {
when (tickets.loadState.refresh) {
is LoadState.Loading -> {
dashboardActivity.startProgressBar()
}
is LoadState.NotLoading -> {
dashboardActivity.stopProgressBar()
Log.e("Not loading", "Not loading")
}
is LoadState.Error -> {
dashboardActivity.stopProgressBar()
}
}
}
LazyColumn(
contentPadding = PaddingValues(bottom = 16.dp),
modifier = Modifier
.fillMaxHeight()
.fillMaxWidth()
.background(Color.White)
) {
stickyHeader {
Row(verticalAlignment = Alignment.CenterVertically,
modifier = Modifier
.fillMaxWidth()
.background(color = colorResource(id = R.color.white))) {
Image(painter = painterResource(id = R.drawable.ic_back),
contentDescription = null,
modifier = Modifier
.wrapContentSize()
.padding(20.dp))
Text(text = "Need Help",
fontSize = 16.sp,
fontFamily = lato,
fontWeight = FontWeight.Bold,
modifier = Modifier.padding(12.dp))
}
}
item {
Text(text = "Select Type of Issue", fontSize = 14.sp,
fontFamily = lato,
fontWeight = FontWeight.Bold,
modifier = Modifier.padding(20.dp))
}
issueTypes.data?.let {
items(it.issueData.windowed(size = 3,
step = 3,
partialWindows = true)) { subList ->
Row(horizontalArrangement = Arrangement.SpaceAround,
modifier = Modifier
.fillMaxWidth()) {
subList.forEach { issueData ->
IssueType(issueType = issueData)
}
}
}
}
item {
Row(horizontalArrangement = Arrangement.Center,
modifier = Modifier
.background(color = colorResource(id = R.color.light_blue))
.fillMaxWidth()
.padding(vertical = 20.dp)) {
Image(painter = painterResource(id = R.drawable.ic_phone),
contentDescription = null)
Spacer(modifier = Modifier.width(width = 20.dp))
Text(
text = "Contact us on [phone]",
fontSize = 14.sp,
fontFamily = lato,
fontWeight = FontWeight.Bold,
)
}
}
item {
Text(text = "Past Issues",
color = colorResource(id = R.color.secondary),
fontSize = 16.sp,
fontFamily = lato,
fontWeight = FontWeight.Bold,
modifier = Modifier.padding(start = 20.dp, top = 32.dp, bottom = 16.dp))
}
tickets.apply {
if (itemCount > 0) {
items(this, key = {
it.ticketId
}) { ticket ->
ticket?.let { TicketView(ticket = it) }
}
}
}
}
}
ApiResource.Status.ERROR -> {
dashboardActivity.stopProgressBar()
}
ApiResource.Status.LOADING -> {
dashboardActivity.startProgressBar()
}
}
}

Answer 1

试着让loadStateListener在不同的可组合

@Composable
fun <T : Any> pagingLoadingState(
dashboardActivity: DashboardActivity,
pagingItems: LazyPagingItems<T>,
showLoadState: (pagingState: PagingEnum) -> Unit,
isLoaded: (() -> Unit)? = null
) {
pagingItems.loadState.apply {
when {
append is LoadState.Loading -> {
showLoadState(PagingEnum.LOADING)
}
append is LoadState.NotLoading -> {
showLoadState(PagingEnum.FINISHED)
}
append is LoadState.Error -> {
showLoadState(PagingEnum.ERROR)
}
refresh is LoadState.Loading -> {
dashboardActivity.startProgressBar()
}
refresh is LoadState.NotLoading -> {
dashboardActivity.stopProgressBar()
if (isLoaded != null) {
isLoaded()
}
}
refresh is LoadState.Error -> {
dashboardActivity.stopProgressBar()
}
}
}
}

如果将来有人有任何问题，请告诉我