如何在JetPack组成的LazyColumn中添加项目？
生成一个项目列表，
private val _balloonsStatus =
MutableStateFlow<Status<List<BalloonsQuery.Edge>?>>(Status.Loading())
val balloonsStatus get() = _balloonsStatus
private val _endCursor = MutableStateFlow<String?>(null)
val endCursor get() = _endCursor
init {
loadBalloons(null)
}
fun loadBalloons(cursor: String?) {
viewModelScope.launch {
val data = repo.getBalloonsFromServer(cursor)
if (data.errors == null) {
_balloonsStatus.value = Status.Success(data.data?.balloons?.edges)
_endCursor.value = data.data?.balloons?.pageInfo?.endCursor
} else {
_balloonsStatus.value = Status.Error(data.errors!![0].message)
_endCursor.value = null
}
}
}
在以下视图模型代码中，我正在从GraphQl Server和Composobable函数中
@Composable
fun BalloonsScreen(
navHostController: NavHostController? = null,
viewModel: SharedBalloonViewModel
) {
val endCursor by viewModel.endCursor.collectAsState()
val balloons by viewModel.balloonsStatus.collectAsState()
AssignmentTheme {
Column(modifier = Modifier.fillMaxSize()) {
when (balloons) {
is Status.Error -> {
Log.i("Reyjohn", balloons.message!!)
}
is Status.Loading -> {
Log.i("Reyjohn", "loading..")
}
is Status.Success -> {
BalloonList(edgeList = balloons.data!!, navHostController = navHostController)
}
}
Spacer(modifier = Modifier.weight(1f))
Button(onClick = { viewModel.loadBalloons(endCursor) }) {
Text(text = "Load More")
}
}
}
}
@Composable
fun BalloonList(
edgeList: List<BalloonsQuery.Edge>,
navHostController: NavHostController? = null,
) {
LazyColumn {
items(items = edgeList) { edge ->
UserRow(edge.node, navHostController)
}
}
}
我通过遵循此代码来获取此数据：但是问题是每次我单击加载更多 tusta再生视图并显示一组新列表，但是我想在上一个列表末尾附加列表。据我了解，随着我正在听的流程的重新生成，这是在做这件事背后的工作，但是我坚持在这里进行有关如何在这里实现目标的解决方法，这将是一个善良的帮助！
In the following viewModel code I am generating a list of items from graphQl server
private val _balloonsStatus =
MutableStateFlow<Status<List<BalloonsQuery.Edge>?>>(Status.Loading())
val balloonsStatus get() = _balloonsStatus
private val _endCursor = MutableStateFlow<String?>(null)
val endCursor get() = _endCursor
init {
loadBalloons(null)
}
fun loadBalloons(cursor: String?) {
viewModelScope.launch {
val data = repo.getBalloonsFromServer(cursor)
if (data.errors == null) {
_balloonsStatus.value = Status.Success(data.data?.balloons?.edges)
_endCursor.value = data.data?.balloons?.pageInfo?.endCursor
} else {
_balloonsStatus.value = Status.Error(data.errors!![0].message)
_endCursor.value = null
}
}
}
and in the composable function I am getting this data by following this code:
@Composable
fun BalloonsScreen(
navHostController: NavHostController? = null,
viewModel: SharedBalloonViewModel
) {
val endCursor by viewModel.endCursor.collectAsState()
val balloons by viewModel.balloonsStatus.collectAsState()
AssignmentTheme {
Column(modifier = Modifier.fillMaxSize()) {
when (balloons) {
is Status.Error -> {
Log.i("Reyjohn", balloons.message!!)
}
is Status.Loading -> {
Log.i("Reyjohn", "loading..")
}
is Status.Success -> {
BalloonList(edgeList = balloons.data!!, navHostController = navHostController)
}
}
Spacer(modifier = Modifier.weight(1f))
Button(onClick = { viewModel.loadBalloons(endCursor) }) {
Text(text = "Load More")
}
}
}
}
@Composable
fun BalloonList(
edgeList: List<BalloonsQuery.Edge>,
navHostController: NavHostController? = null,
) {
LazyColumn {
items(items = edgeList) { edge ->
UserRow(edge.node, navHostController)
}
}
}
but the problem is every time I click on Load More button it regenerates the view and displays a new set of list, but I want to append the list at the end of the previous list. As far I understand that the list is regenerated as the flow I am listening to is doing the work behind this, but I am stuck here to get a workaround about how to achieve my target here, a kind hearted help would be much appreciated!
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list＆lt; balloonsquery.gedge＆gt;？
该列表添加
您
可以在ViewModel中创建一个私有列表，
You can create a private list in ViewModel that adds
List<BalloonsQuery.Edge>?>and instead of
you can do something like
should update Compose with the latest data appended to existing one