Search，FocusRequester不是初始化的

Question

但是我有一个错误

   FocusRequester is not initialized. Here are some possible fixes:
   1. Remember the FocusRequester: val focusRequester = remember { FocusRequester() }
   2. Did you forget to add a Modifier.focusRequester() ?
   3. Are you attempting to request focus during composition? Focus requests should be made in
   response to some event. Eg Modifier.clickable { focusRequester.requestFocus() }

我得出的结论是，这是由于动画性可见性所致，因为没有它，一切都起作用。也就是说，当按钮和搜索最初可见时，一切都起作用。 我认为光标无处可站立，因为它没有立即更新，但我不知道该怎么做

我的代码：

topBar = {
                TopAppBar(
                    actions = {
                       // val keyboardController = LocalSoftwareKeyboardController.current //val focusRequester = remember { FocusRequester() }
                        var visibleSearchBar by remember {
                            mutableStateOf(false)
                        }
                        var visiblecurrentSearch by remember {
                            mutableStateOf(true)
                        }
                        val state = remember { mutableStateOf(TextFieldValue("")) }
                        AnimatedVisibility(visible = visiblecurrentSearch) {
                            IconButton(onClick = {
                                visibleSearchBar = true
                                visiblecurrentSearch = false
                                //focusRequester.requestFocus()
                                //keyboardController?.show()
                            }) {
                                Icon(painter = painterResource(id = R.drawable.ic_baseline_search_24),
                                    contentDescription = "search")
                            }
                        }
                        AnimatedVisibility(visible = visibleSearchBar) {
                            TextField(
                                value = state.value,
                                onValueChange = { value ->
                                    state.value = value
                                },
                                enabled = true,
                                shape = RoundedCornerShape(25.dp),
                                modifier = Modifier
                                    //.focusRequester(focusRequester)
                                    .fillMaxWidth()
                                    .padding(end = 10.dp)
                                    .scale(scaleX = 1F, scaleY = 0.9F),
                                textStyle = TextStyle(color = Color.Black),
                                placeholder = {
                                    Text(
                                        text = "Search",
                                        fontSize = 14.sp,
                                    )
                                },
                                keyboardActions = KeyboardActions(
                                    onDone = {
                                        //movie = list
                                    }
                                ),
                                leadingIcon = {
                                    Icon(
                                        Icons.Default.Search,
                                        contentDescription = "",
                                        modifier = Modifier
                                            .size(20.dp)
                                    )
                                },
                                trailingIcon = {
                                    IconButton(
                                        onClick = {
                                            state.value =
                                                TextFieldValue("") =
                                            visibleSearchBar = false
                                            visiblecurrentSearch = true
                                        }
                                    ) {
                                        Icon(
                                            Icons.Default.Close,
                                            contentDescription = "",
                                            modifier = Modifier
                                                .size(20.dp)
                                        )
                                    }

                                },
                                singleLine = true,
                                colors = TextFieldDefaults.textFieldColors(
                                    textColor = Color.Black,
                                    cursorColor = Color.Black,
                                    leadingIconColor = Color.Black,
                                    trailingIconColor = Color.Black,
                                    focusedIndicatorColor = Color.Transparent,
                                    unfocusedIndicatorColor = Color.Transparent,
                                    disabledIndicatorColor = Color.Black
                                )
                            )
                        }


                    },
                    title = {

                    },
                    navigationIcon = {
                        IconButton(onClick = {}) {
                            Icon(painter = painterResource(id = R.drawable.ic_baseline_menu_24),
                                contentDescription = "menu")
                        }
                    },
                    backgroundColor = Color.White,
                    contentColor = Color.Black,
                    elevation = 3.dp
                )
            }

您可以使用副作用来要求焦点。 类似：

    val focusRequester = remember { FocusRequester() }
    LaunchedEffect(visibleSearchBar){
        if (visibleSearchBar)
            focusRequester.requestFocus()
    }

    AnimatedVisibility(visible = visibleSearchBar) {
        TextField(
            //...
            modifier = Modifier
                .focusRequester(focusRequester)
                .fillMaxWidth()
                .padding(end = 10.dp)
                .scale(scaleX = 1F, scaleY = 0.9F),

           //...
         )

我参加聚会很晚，但是我最近遇到了同样的问题...如果您使用M3，则需要与您的Textfields一起使用modifier.menuanchor（） - >

https：//www.composables.com/components/material3/exposeddropdownmenubox

Answer 1

 ExposedDropdownMenuBox(
        expanded = expanded,
        onExpandedChange = {
            expanded = !expanded
        }
    ) {
        OutlineTextField(
            modifier = Modifier
                .menuAnchor(),
            text = text,
            label = label,
... more stuff

希望它可以帮助更多的人！

Answer 2

根据建议的可能修复程序，尝试在副作用中使用FocusRequester

val focusRequester = remember { FocusRequester() }
LaunchedEffect(visibleSearchBar){
    if (visibleSearchBar)
        focusRequester.requestFocus()
}

topBar = {
            TopAppBar(
                actions = {
                   // val keyboardController = LocalSoftwareKeyboardController.current //val focusRequester = remember { FocusRequester() }
                    var visibleSearchBar by remember {
                        mutableStateOf(false)
                    }
                    var visiblecurrentSearch by remember {
                        mutableStateOf(true)
                    }
                    val state = remember { mutableStateOf(TextFieldValue("")) }
                    AnimatedVisibility(visible = visiblecurrentSearch) {
                        IconButton(onClick = {
                            visibleSearchBar = true
                            visiblecurrentSearch = false
                            //focusRequester.requestFocus()
                            //keyboardController?.show()
                        }) {
                            Icon(painter = painterResource(id = R.drawable.ic_baseline_search_24),
                                contentDescription = "search")
                        }
                    }
                    AnimatedVisibility(visible = visibleSearchBar) {
                        TextField(
                            value = state.value,
                            onValueChange = { value ->
                                state.value = value
                            },
                            enabled = true,
                            shape = RoundedCornerShape(25.dp),
                            modifier = Modifier
                                .focusRequester(focusRequester)
                                .fillMaxWidth()
                                .padding(end = 10.dp)
                                .scale(scaleX = 1F, scaleY = 0.9F),
                            textStyle = TextStyle(color = Color.Black),
                            placeholder = {
                                Text(
                                    text = "Search",
                                    fontSize = 14.sp,
                                )
                            },
                            keyboardActions = KeyboardActions(
                                onDone = {
                                    //movie = list
                                }
                            ),
                            leadingIcon = {
                                Icon(
                                    Icons.Default.Search,
                                    contentDescription = "",
                                    modifier = Modifier
                                        .size(20.dp)
                                )
                            },
                            trailingIcon = {
                                IconButton(
                                    onClick = {
                                        state.value =
                                            TextFieldValue("") =
                                        visibleSearchBar = false
                                        visiblecurrentSearch = true
                                    }
                                ) {
                                    Icon(
                                        Icons.Default.Close,
                                        contentDescription = "",
                                        modifier = Modifier
                                            .size(20.dp)
                                    )
                                }

                            },
                            singleLine = true,
                            colors = TextFieldDefaults.textFieldColors(
                                textColor = Color.Black,
                                cursorColor = Color.Black,
                                leadingIconColor = Color.Black,
                                trailingIconColor = Color.Black,
                                focusedIndicatorColor = Color.Transparent,
                                unfocusedIndicatorColor = Color.Transparent,
                                disabledIndicatorColor = Color.Black
                            )
                        )
                    }


                },
                title = {

                },
                navigationIcon = {
                    IconButton(onClick = {}) {
                        Icon(painter = painterResource(id = R.drawable.ic_baseline_menu_24),
                            contentDescription = "menu")
                    }
                },
                backgroundColor = Color.White,
                contentColor = Color.Black,
                elevation = 3.dp
            )
        }

我还没有潜入DeepInto，但是这里不是那么好的解决方案，即使在添加了启动效果之后，仍然面临问题。

    LaunchedEffect(key1 = Unit, block = {
            delay(200)
            amountField.requestFocus()
    })

我添加了一个杂货延迟。

Answer 3