状态值更改时屏幕未重新组合-Jetpack Compose

Question

这是一个视频通话屏幕。它需要令牌和通道名称才能工作，这需要传递给init调用引擎。我将这些存储在一个用作可变状态的数据类中。

屏幕状态数据类

@Keep
data class CallScreenState(
val callerId: Int? = null,
val recieverId: Int? = null,
val chatRoom: ChatRoom.Data? = null,
val rtcToken: AgoraTokenResponse.TokenData? = null
)

并且在视图模型初始化状态下通过以下代码：

var callScreenState by mutableStateOf(CallScreenState())

在聊天室和令牌api的成功响应视图模型中，状态会用这段代码更新。

callScreenState = callScreenState.copy(
chatRoom = chatRoom.data,//from response
rtcToken = token.data   //from response
)

从这里开始，预计将使用聊天室和rtcToken的新更新值重新组合屏幕

在可组合中

val screenState = remember {
viewModel.callScreenState
}

该屏幕状态用于将值传递给初始化引擎

val mEngine = remember {
initEngine(
context,
object : IRtcEngineEventHandler() {
override fun onJoinChannelSuccess(channel: String?, uid: Int, elapsed: Int) {
Timber.e("hhp-CallScreen onJoinChannelSuccess channel:$channel,uid:$uid,elapsed:$elapsed")
}
override fun onUserJoined(uid: Int, elapsed: Int) {
Timber.e("hhp-CallScreen onUserJoined:$uid")
val desiredUserList = remoteUserMap.toMutableMap()
desiredUserList[uid] = null
remoteUserMap = desiredUserList.toMap() as HashMap<Int, TextureView?>
}
override fun onUserOffline(uid: Int, reason: Int) {
Timber.e("hhp-CallScreen onUserOffline:$uid")
val desiredUserList = remoteUserMap.toMutableMap()
desiredUserList.remove(uid)
remoteUserMap = desiredUserList.toMap() as HashMap<Int, TextureView?>
}
override fun onNetworkQuality(uid: Int, txQuality: Int, rxQuality: Int) {
Timber.e("hhp-CallScreen onNetworkQuality $uid $txQuality $rxQuality")
}
},
screenState.chatRoom?.channelName ?: "",  //Not recomposing when value changes in viewmodel
viewModel.userRole,
token = screenState.rtcToken?.token ?: "" //Not recomposing when value changes in viewmodel
)
}

这是initEngine函数创建

fun initEngine(
current: Context,
eventHandler: IRtcEngineEventHandler,
channelName: String,
userRole: String,
token: String
): RtcEngine =
RtcEngine.create(current, BuildConfig.AGORA_APPID, eventHandler).apply {
enableVideo()
setChannelProfile(1)
if (userRole == "Broadcaster") {
setClientRole(1)
} else {
setClientRole(0)
}
//Expected to be recomposed when screen state value updated with new values
joinChannel(token, channelName, "", 0)
}

我一开始就知道，在api调用之前，屏幕状态中的通道名称和令牌是空的。一旦获取令牌和聊天室的api成功，屏幕状态就会从viewmodel更新，我希望initEngine fun会再次被调用，因为它应该会重新组合。但事实并非如此。我是不是错过了什么？当屏幕状态内的频道名称值发生变化时，如何重新组合？

Answer 1

我无法理解您的整个用例，但您是否尝试过将key指定为remember？

如何在屏幕内更改频道名称值时重新组合sctate更改？

您可以尝试其中任何一种，尽管我不确定它们是否能解决您的问题，但当您将key提供给remember并且它发生更改时，它将为re-calculate，假设remember's之前计算使用的channelName在下一个re-composition上会有所不同。

这个，

val screenState = remember(key1 = channelname) {
viewModel.callScreenState
}

或者这个

val mEngine = remember(key1 = channelname) { ... }