【发布时间】：2021-11-14 00:09:02
【问题描述】：
我在 Controller 类中定义了一个名为 data 的变量。我在 fillWordlist 方法中收到了上面提到的错误。我在视图类的 historyWordList 方法中创建了 listview.builder。但列表没有出现在屏幕上，我收到此错误。 'List
控制器类
class WordController extends GetxController {
TextEditingController controllerInput1 = TextEditingController();
TextEditingController controllerInput2 = TextEditingController();
RxBool active2 = false.obs;
final translator = GoogleTranslator();
RxList data = <Word>[].obs;
@override
void onInit() {
fillWordList();
super.onInit();
}
onClickIconButtonFavori() {
if (controllerInput1.text.isNotEmpty && controllerInput2.text.isNotEmpty) {
addNote();
clear();
}
}
showText() {
if (active2.value == true) {
return;
}
active2.toggle();
}
ekle(Word word) async {
var val = await WordRepo().add(word);
showDilog("Kayıt Başarılı");
update();
return val;
}
updateWord(Word word) async {
var val = await WordRepo().update(word);
showDilog("Kayıt Başarılı");
return val;
}
deleteWord(int? id) async {
var val = await WordRepo().deleteById(id!);
return val;
}
fillWordList() async {
data.value = await WordRepo().getAll();
}
translateLanguage(String newValue) async {
if (newValue == null || newValue.length == 0) {
return;
}
List list = ["I", "i"];
if (newValue.length == 1 && !list.contains(newValue)) {
return;
}
var translate = await translator.translate(newValue, from: 'en', to: 'tr');
controllerInput2.text = translate.toString();
return translate;
}
showDilog(String message) {
Get.defaultDialog(title: "Bilgi", middleText: message);
}
addNote() async {
var word =
Word(wordEn: controllerInput1.text, wordTr: controllerInput2.text);
await ekle(word);
fillWordList();
}
clear() {
controllerInput2.clear();
controllerInput1.clear();
}
updateNote() async {
var word =
Word(wordEn: controllerInput1.text, wordTr: controllerInput2.text);
await updateWord(word);
await fillWordList();
update();
}
}
查看类：Main_page.dart
class MainPage extends StatelessWidget {
String _firstLanguage = "English";
String _secondLanguage = "Turkish";
WordController controller = Get.put(WordController());
final _formKey = GlobalKey<FormState>();
@override
Widget build(BuildContext context) {
return Scaffold(
drawer: _drawer,
backgroundColor: Colors.grey.shade300,
appBar: _appbar,
body: _bodyScaffold,
floatingActionButton: _floattingActionButton,
);
}
SingleChildScrollView get _bodyScaffold {
return SingleChildScrollView(
child: Column(
children: [
chooseLanguage,
translateTextView,
//futureBuilder,
],
),
);
}
AppBar get _appbar {
return AppBar(
backgroundColor: Colors.blueAccent,
centerTitle: true,
title: Text("TRANSLATE"),
elevation: 0.0,
);
}
get chooseLanguage => Container(
height: Get.height / 12.0,
decoration: buildBoxDecoration,
child: Row(
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
firstChooseLanguage,
changeLanguageButton,
secondChooseLanguage,
],
),
);
get buildBoxDecoration {
return BoxDecoration(
color: Colors.white,
border: Border(
bottom: BorderSide(
width: 3.5,
color: Colors.grey,
),
),
);
}
get translateTextView => Column(
children: [
Card(
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.all(Radius.circular(8.0)),
),
margin: EdgeInsets.only(left: 2.0, right: 2.0, top: 2.0),
child: _formTextField,
),
Obx(
() => Container(
height: controller.active2 == true
? Get.height / 2.3
: Get.height / 1.6,
child: historyWordList,
),
)
],
);
Widget get historyWordList {
return ListView.builder(
itemCount: controller.data.length,
itemBuilder: (context, index) {
return Card(
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.all(Radius.circular(5.0)),
),
margin: EdgeInsets.only(left: 8.0, right: 8.0, top: 0.8),
child: Container(
color: Colors.white30,
padding: EdgeInsets.only(left: 8.0, top: 8.0, bottom: 8.0),
child: Row(
crossAxisAlignment: CrossAxisAlignment.start,
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Obx(()=>Column(
crossAxisAlignment: CrossAxisAlignment.start,
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: [
firstText(controller.data[index].value),
secondText(controller.data[index].value),
],
)),
historyIconbutton,
],
),
),
);
},
);
}
get _formTextField {
return Form(
key: _formKey,
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Container(
color: Colors.white30,
height: Get.height / 6.0,
padding: EdgeInsets.only(left: 16.0, top: 8.0, bottom: 8.0),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
textFormFieldEntr, //one textfield
favoriIconButton,
],
),
),
textFormField, //burası kapandı // second
],
),
);
}
get textFormFieldEntr {
return Flexible(
child: Container(
height: Get.height / 5.2,
child: TextFormField(
readOnly: true, //sadece okuma
onTap: () {
showMaterialBanner();
},
controller: controller.controllerInput1,
onChanged: (text) {
if (text.isEmpty) {
controller.active2(false);
} else {
controller.active2(true);
}
},
maxLines: 6,
decoration: InputDecoration(
hintText: "Enter",
contentPadding: const EdgeInsets.symmetric(vertical: 5.0),
),
),
),
);
}
void showMaterialBanner() {
ScaffoldMessenger.of(Get.context!).showMaterialBanner(MaterialBanner(
backgroundColor: Colors.white,
content: Padding(
padding: const EdgeInsets.only(top: 40.0),
child: Column(
children: [
TextFormField(
controller: controller.controllerInput1,
maxLines: 7,
onChanged: (text) {
controller.translateLanguage(text);
if (text.isNotEmpty) {
controller.showText();
}
// controller.showText();
},
decoration: InputDecoration(
suffixIcon: IconButton(
onPressed: () {
if (controller.controllerInput1.text.length > 0) {
controller.clear();
} else {
controller.clear();
closeBanner();
}
},
icon: Icon(Icons.clear),
),
contentPadding: const EdgeInsets.symmetric(vertical: 5.0),
),
),
SizedBox(height: Get.height / 6.0),
TextFormField(
controller: controller.controllerInput2,
maxLines: 7,
onTap: () {
if (controller.controllerInput1.text.isEmpty) {
controller.clear();
} else {
controller.addNote();
}
closeBanner();
},
decoration: InputDecoration(
contentPadding: const EdgeInsets.symmetric(vertical: 5.0),
),
),
],
),
),
actions: [
IconButton(
onPressed: () {
closeBanner();
},
icon: Icon(null),
),
]));
}
void closeBanner() {
ScaffoldMessenger.of(Get.context!).hideCurrentMaterialBanner();
}
get textFormField {
return Obx(() {
return Container(
child: Visibility(
visible: controller.active2.value, //false
child: Container(
color: Colors.white30,
height: Get.height / 5.2,
padding:
EdgeInsets.only(left: 16.0, right: 42.0, top: 8.0, bottom: 8.0),
child: TextFormField(
readOnly: true,
controller: controller.controllerInput2,
maxLines: 6,
decoration: InputDecoration(
contentPadding: const EdgeInsets.symmetric(vertical: 5.0),
),
),
),
),
);
});
}
IconButton get historyIconbutton {
return IconButton(
onPressed: () {},
icon: Icon(Icons.history),
iconSize: 30.0,
);
}
Text firstText(Word word) {
return Text(
"İngilizce: ${word.wordEn ?? ""}",
style: TextStyle(
fontWeight: FontWeight.w600,
),
maxLines: 1,
overflow: TextOverflow.ellipsis,
);
}
get changeLanguageButton {
return Material(
color: Colors.white,
child: IconButton(
icon: Icon(
Icons.wifi_protected_setup_rounded,
color: Colors.indigo,
size: 30.0,
),
onPressed: () {},
),
);
}
get secondChooseLanguage {
return Expanded(
child: Material(
color: Colors.white,
child: InkWell(
onTap: () {},
child: Center(
child: Text(
this._secondLanguage,
style: TextStyle(
color: Colors.blue[600],
fontSize: 22.0,
),
),
),
),
),
);
}
get firstChooseLanguage {
return Expanded(
child: Material(
color: Colors.white,
child: InkWell(
onTap: () {},
child: Center(
child: Text(
this._firstLanguage,
style: TextStyle(
color: Colors.blue[600],
fontSize: 22.0,
),
),
),
),
),
);
}
Text secondText(Word word) {
return Text(
"Türkçe: ${word.wordTr ?? ""}",
style: TextStyle(
fontWeight: FontWeight.w400,
),
maxLines: 1,
overflow: TextOverflow.ellipsis,
);
}
get favoriIconButton {
return IconButton(
alignment: Alignment.topRight,
onPressed: controller.onClickIconButtonFavori,
icon: Icon(
Icons.forward,
color: Colors.blueAccent,
size: 28.0,
),
);
}
FloatingActionButton get _floattingActionButton {
return FloatingActionButton(
onPressed: () {
Get.to(WordListPage());
},
child: Icon(
Icons.app_registration,
size: 30,
),
);
}
Drawer get _drawer {
return Drawer(
child: ListView(
// Important: Remove any padding from the ListView.
padding: EdgeInsets.zero,
children: <Widget>[
userAccountsDrawerHeader,
drawerFavorilerim,
drawersettings,
drawerContacts,
],
),
);
}
ListTile get drawerContacts {
return ListTile(
leading: Icon(Icons.contacts),
title: Text("Contact Us"),
onTap: () {
Get.back();
},
);
}
ListTile get drawersettings {
return ListTile(
leading: Icon(Icons.settings),
title: Text("Settings"),
onTap: () {
Get.back();
},
);
}
ListTile get drawerFavorilerim {
return ListTile(
leading: Icon(
Icons.star,
color: Colors.yellow,
),
title: Text("Favorilerim"),
onTap: () {
Get.to(FavoriListPage());
},
);
}
UserAccountsDrawerHeader get userAccountsDrawerHeader {
return UserAccountsDrawerHeader(
accountName: Text("UserName"),
accountEmail: Text("E-mail"),
currentAccountPicture: CircleAvatar(
backgroundColor: Colors.grey,
child: Text(
"",
style: TextStyle(fontSize: 40.0),
),
),
);
}
}
【问题讨论】：
标签： list flutter function dart listview