我一直在做一个字典应用程序有一段时间了，我补充说，用户可以创建自己的字典在我的应用程序上。我显示用户的字典在屏幕上，用户可以删除他们的字典，无论他们想要什么。所以我试图使警报对话框，因为我希望用户不要删除他们的字典时，他们直接按下删除图标。屏幕上会出现一个警告对话框，在那个警告对话框中应该有两个按钮，比如取消和接受。如果用户按下接受，也就是说，如果他想删除，我希望字典被删除。
然而，问题是在编写和我写的代码中很难实现这一点，因为我遇到了很多问题，而这本应该很容易。我在我的代码中所做的是，如果用户单击删除图标，onDeleteClick将工作，showAlertDialog在onDeleteClick中变为true。当为true时，它进入顶部的if块并调用alertdialog组件。当alertdialog组件被调用时，CustomDialogUI打开。我向CustomDialogUI发送了两个参数，一个是showAlertDialog的mutablestate，它控制alertdialog的打开并且第二个是deleteDicState。如果用户在打开的警告对话框中说允许，则deleteDicState变为真，并且如果deleteDicState为真，则必须进行删除。
由于deleteDicState第一次是假的，它不删除，但当警报对话框第二次打开，我说删除，它删除它出于某种原因，我如何解决这个问题的帮助。
我的代码
@Composable
fun CreateYourOwnDictionaryScreen(
navController: NavController,
viewModel: CreateYourOwnDictionaryViewModel = hiltViewModel()
) {
val scaffoldState = rememberScaffoldState()
val state = viewModel.state.value
val scope = rememberCoroutineScope()
val context = LocalContext.current
val showAlertDialog = remember { mutableStateOf(false) }
val deleteDicState = remember { mutableStateOf(false) }
if(showAlertDialog.value){
Dialog(onDismissRequest = { showAlertDialog.value = false }) {
CustomDialogUI(openDialogCustom = showAlertDialog,deleteDicState)
}
}
Scaffold(
scaffoldState = scaffoldState,
topBar = {
TopAppBar(
backgroundColor = bar,
title = {
androidx.compose.material3.Text(
text = "your dictionaries",
modifier = Modifier.fillMaxWidth(),
color = Color.White,
fontSize = 22.sp
)
},
navigationIcon = {
IconButton(onClick = {
navController.navigate(Screen.MainScreen.route)
}) {
Icon(
imageVector = Icons.Filled.ArrowBack,
contentDescription = "Go Back"
)
}
}
)
},
floatingActionButtonPosition = FabPosition.Center,
floatingActionButton = {
FloatingActionButton(
onClick = { navController.navigate(Screen.CreateDicScreen.route) },
backgroundColor = bar,
) {
Icon(Icons.Filled.Add, "fab")
}
}
) {
Box(modifier = Modifier.background(MaterialTheme.colors.background)) {
Column(
modifier = Modifier
.fillMaxSize()
.padding(16.dp)
) {
LazyColumn(
modifier = Modifier.fillMaxSize()
) {
items(state.dictionaries) { dictionary ->
CreateYourOwnDictionaryItem(
dictionary = dictionary,
modifier = Modifier
.fillMaxWidth()
.clickable {
navController.navigate(Screen.MyWordsScreen.passDicId(dictionary.uid))
},
onAddClick = {
navController.navigate(
Screen.MakeYourDictionaryScreen.passDicId(
dictionary.uid
)
)
},
onDeleteClick = {
if(deleteDicState.value){
viewModel.onEvent(
CreateYourOwnDictionaryEvents.DeleteDictionary(dictionary)
)
scope.launch {
val result = scaffoldState.snackbarHostState.showSnackbar(
message = "dictionary is deleted",
/*actionLabel = "Undo",*/
duration = SnackbarDuration.Short
)
}
}
},
onEditClick = {
navController.navigate(
Screen.UpdateOwnDictionaryScreen.passDicIdAndDicName(
dictionary.uid,
dictionary.creationTime,
)
)
}
)
}
}
}
}
}
}
@Composable
fun CustomDialogUI(
openDialogCustom: MutableState<Boolean>,
deleteDicState : MutableState<Boolean>
) {
Card(
//shape = MaterialTheme.shapes.medium,
shape = RoundedCornerShape(10.dp),
// modifier = modifier.size(280.dp, 240.dp)
modifier = Modifier.padding(10.dp, 5.dp, 10.dp, 10.dp),
elevation = 8.dp
) {
Column(
modifier = Modifier
.background(Color.White)
) {
//.......................................................................
Image(
painter = painterResource(id = R.drawable.ic_baseline_warning),
contentDescription = null, // decorative
/*contentScale = ContentScale.Fit,
colorFilter = ColorFilter.tint(
color = bar
),*/
modifier = Modifier
.padding(top = 35.dp)
.height(70.dp)
.fillMaxWidth(),
)
Column(modifier = Modifier.padding(16.dp)) {
androidx.compose.material3.Text(
text = "Warning !",
textAlign = TextAlign.Center,
modifier = Modifier
.padding(top = 5.dp)
.fillMaxWidth(),
style = MaterialTheme.typography.body2,
maxLines = 2,
overflow = TextOverflow.Ellipsis
)
androidx.compose.material3.Text(
text = "Are you sure that your previously created dictionary will be deleted?",
textAlign = TextAlign.Center,
modifier = Modifier
.padding(top = 10.dp, start = 25.dp, end = 25.dp)
.fillMaxWidth(),
)
}
//.......................................................................
Row(
Modifier
.fillMaxWidth()
.padding(top = 10.dp)
.background(bar),
horizontalArrangement = Arrangement.SpaceAround
) {
TextButton(onClick = {
openDialogCustom.value = false
}) {
Text(
"Not Now",
fontWeight = FontWeight.Bold,
color = Color.Black,
modifier = Modifier.padding(top = 5.dp, bottom = 5.dp)
)
}
TextButton(onClick = {
openDialogCustom.value = false
deleteDicState.value = true
}) {
Text(
"Allow",
fontWeight = FontWeight.ExtraBold,
color = Color.Black,
modifier = Modifier.padding(top = 5.dp, bottom = 5.dp)
)
}
}
}
}
}我不能在onDeleteClick中调用CustomDialogUI。如果我调用它，它会给出以下错误@Composable invocations can only happen from the context of a @Composable function。
例如这样
一米十三分一秒
onDeleteClick = {
Dialog(onDismissRequest = { showAlertDialog.value = false }) {
CustomDialogUI(openDialogCustom = showAlertDialog,deleteDicState)
}
...."我不能这样打电话"
因此，我在onDeleteClick外部调用它，或者直接在CustomDialogUI中调用它。如果用户按下删除按钮，我无法在那里删除它，因为我无法在那里访问viewmodel和字典
例如这样
一月十六日一月
TextButton(onClick = {
openDialogCustom.value = false
viewModel.onEvent(
CreateYourOwnDictionaryEvents.DeleteDictionary(dictionary)
)
scope.launch {
val result = scaffoldState.snackbarHostState.showSnackbar(
message = "dictionary is deleted",
/*actionLabel = "Undo",*/
duration = SnackbarDuration.Short
)
}
}) {
Text(
"Allow",
fontWeight = FontWeight.ExtraBold,
color = Color.Black,
modifier = Modifier.padding(top = 5.dp, bottom = 5.dp)
)
}
}"我不能这样打电话"
1条答案
按热度按时间0yg35tkg1#
将
MutableStates作为可组合参数传递被认为是一种不好的做法，您应该改为传递原始值和回调。在您的情况下，您可以这样实现它：