Android Jetpack Composable不';不要对变化做出反应
我一直在努力效仿唯一一个我能找到支持的好例子,但在我的情况下,它不起作用 我有一个Android Jetpack Composable不';不要对变化做出反应,android,android-fragments,android-livedata,android-viewmodel,android-jetpack-compose,Android,Android Fragments,Android Livedata,Android Viewmodel,Android Jetpack Compose,我一直在努力效仿唯一一个我能找到支持的好例子,但在我的情况下,它不起作用 我有一个ViewModel与Composable中的@Model对话,并根据MutableLiveData更改加载:Bool,但它不会重新组合 class LoaderViewModel : ViewModel() { val loadingLiveData = MutableLiveData<Boolean>(false) fun fetch() { viewModelSc
ViewModel
与Composable中的@Model
对话,并根据MutableLiveData
更改加载:Bool
,但它不会重新组合
class LoaderViewModel : ViewModel() {
val loadingLiveData = MutableLiveData<Boolean>(false)
fun fetch() {
viewModelScope.launch {
val flow = flowOf("result")
.onStart {
loadingLiveData.value = true
delay(2000)
}
.onCompletion {
loadingLiveData.value = false
}
.collect {
// Do something with the result
}
}
}
}
class LoaderFragment : Fragment() {
private val viewModel: LoaderViewModel by viewModel()
@Model
class ActivityLoadingState(var loading: Boolean = false)
private val activityLoadingState = ActivityLoadingState()
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
return FrameLayout(context ?: return null).apply {
layoutParams = FrameLayout.LayoutParams(MATCH_PARENT, MATCH_PARENT)
setContent {
Loader()
}
}
}
@Composable
fun Loader() = MaterialTheme {
val loadingModel = activityLoadingState
Container {
Center {
if (loadingModel.loading) {
CircularProgressIndicator(
color = Color(0xFFFF0000)
)
} else {
Container { }
}
}
}
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
subscribeUI()
viewModel.fetch()
}
private fun subscribeUI() {
viewModel.loadingLiveData.observe(viewLifecycleOwner) {
activityLoadingState.loading = it
}
}
}
class LoaderViewModel:ViewModel(){
val loadingLiveData=MutableLiveData(false)
取乐{
viewModelScope.launch{
val流量=流量(“结果”)
.onStart{
loadingLiveData.value=true
延迟(2000年)
}
.未完成{
loadingLiveData.value=false
}
.收集{
//对结果做点什么
}
}
}
}
类LoaderFragment:Fragment(){
private val viewModel:LoaderViewModel by viewModel()
@模型
类ActivityLoadingState(变量加载:Boolean=false)
private val activityLoadingState=activityLoadingState()
覆盖创建视图(
充气机,
容器:视图组?,
savedInstanceState:捆绑?
):查看{
返回帧布局(上下文?:返回空)。应用{
layoutParams=FrameLayout.layoutParams(匹配父项,匹配父项)
设置内容{
加载器()
}
}
}
@组合的
乐趣加载程序()=材料主题{
val loadingModel=activityLoadingState
容器{
居中{
if(加载模型。加载){
循环压缩机指示器(
颜色=颜色(0xFFFF0000)
)
}否则{
容器{}
}
}
}
}
覆盖已创建的视图(视图:视图,保存状态:捆绑?){
super.onViewCreated(视图,savedInstanceState)
subscribeUI()
viewModel.fetch()
}
私人娱乐订阅界面(){
viewModel.loadingLiveData.observe(viewLifecycleOwner){
activityLoadingState.loading=it
}
}
}
我要做的是在我的ViewModel中有流,并在composables中使用函数collectAsState()