所以我制作了这个颤振应用程序，它将单词翻译成baybayin（仍然有关于它的错误，请也帮助我）。该应用程序将有一个使用 Hive 的数据库。它工作得很好。当我重新加载我的应用程序的一部分时，我设法做到了。然后我注意到前几天，当我应该继续设计我的应用程序时，我收到了这个错误
════════ Exception caught by widgets library ═══════════════════════════════════════════════════════
The following NoSuchMethodError was thrown building TranslatePage(dirty, state: _TranslatePageState#347de):
The method 'get' was called on null.
Receiver: null
Tried calling: get(1)
The relevant error-causing widget was:
TranslatePage file:///C:/Users/me/AndroidStudioProjects/baybay_app/lib/Translate/Translate.dart:35:18
When the exception was thrown, this was the stack:
#0 Object.noSuchMethod (dart:core-patch/object_patch.dart:51:5)
#1 _TranslatePageState.build (package:baybay_app/Translate/Translate.dart:189:35)
#2 StatefulElement.build (package:flutter/src/widgets/framework.dart:4744:28)
#3 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:4627:15)
#4 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:4800:11)
...
════════════════════════════════════════════════════════════════════════════════════════════════════
我尝试了在谷歌上找到的方法，我尝试了很多方法，但我总是到这里。如果我重新加载它，它工作正常。但是当我退出翻译药水时（我转到我的 Baybayin 应用程序的主页），它再次显示。每次我重新加载它时它都可以正常工作。当我热启动它时，错误再次显示。我不能一直重新加载它，尤其是当我释放它时，
这是我的代码。如您所见，我尝试了多种方法来解决该错误。我的代码可能不干净。因为我尝试了多种方法。
class Translate extends StatelessWidget {
@override
Widget build(BuildContext context) {
return FutureBuilder(
future:
DefaultAssetBundle.of(context).loadString(
'assets/lang/tl-Fil.json', cache: false),
builder: (context, snapshot) {
List mydata = json.decode(snapshot.data.toString());
if (mydata == null) {
return Scaffold(
body: Center(
child: Text(
"Loading",
),
),
);
} else {
return TranslatePage(mydata: mydata);
}
},
);
}
}
class TranslatePage extends StatefulWidget {
final List mydata;
// final List<TranslatePageLetter> _TranslatePageLetter = TranslatePageletter;
TranslatePage({Key key, @required this.mydata}) : super(key: key);
@override
_TranslatePageState createState() => _TranslatePageState(mydata);
}
class _TranslatePageState extends State<TranslatePage> {
Box box;
// final letters = [
// let(
// englet: "ba",
// bylet: "b"
// ),
// let(englet: "be", bylet: "be"),
// let(englet: "bi", bylet: "bi"),
// let(englet: "bo", bylet: "bo"),
// let(englet: "bu", bylet: "bu"),
// let(englet: "b", bylet: "b+")
// ];
// List<let> letter;
// @override
// void initState() {
// super.initState();
//
// }
Future openBox() async {
var dir = await getApplicationDocumentsDirectory();
Hive.init(dir.path);
box = await Hive.openBox('translate');
return;
}
final List mydata;
_TranslatePageState(this.mydata);
final translate = TextEditingController();
String tagalog;
String translateoutput = "Baybay";
var translatedphrase = '';
int charLength = 0;
String text;
int even = 2;
bool istyping = false;
int keys = 1;
String drop;
// StreamController _streamController;
// Stream _stream;
List<TranslateLetter> translateletter;
_onChanged(String value) {
setState(() {
charLength = value.length;
});
}
@override
void dispose() {
translate.dispose();
super.dispose();
}
void hiveOperation() async {
await openBox();
}
@override
void initState() {
super.initState();
hiveOperation();
// _streamController = StreamController();
// _stream = _streamController.stream;
}
void putdata() {
setState(() {
box.put(keys, translate.text);
});
}
String getdata(keys, String drop) {
setState(() {
if (box.isEmpty == true) {
drop = "Null";
}
else {
drop = box.get(keys);
}
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Center(
child: Text('Translate',
style: TextStyle(
fontFamily: 'Risque',
color: Color.fromARGB(250, 189, 208, 156)
),),
),
backgroundColor: Color.fromARGB(250, 64, 79, 36),
),
body: Column(
mainAxisAlignment: MainAxisAlignment.start,
children: [
RaisedButton(onPressed: () {},
child: Text('Guide')),
Expanded(
child: Container(child: Column(
children: [
TextField(
controller: translate,
autocorrect: true,
decoration: InputDecoration(
hintText: 'Enter Some Text Here',
suffixIcon: IconButton(
icon: Icon(Icons.arrow_drop_down,),
onPressed: () {
},
)),
onChanged: _onChanged,
),
DropdownButton(
items: [
DropdownMenuItem<String>(
child: Text(
box.get(1)
),
onTap: () {
translate.text = box.get(1);
},
),
DropdownMenuItem(
value: box.get(2),
child: Text(
box.get(2),
),
onTap: () {
translate.text = box.get(2);
},),
DropdownMenuItem(
value: box.get(3),
child: Text(
box.get(3),
),
onTap: () {
translate.text = box.get(3);
},),
DropdownMenuItem(
value: box.get(4),
child: Text(
box.get(4),
),
onTap: () {
translate.text = box.get(4);
},),
DropdownMenuItem(
value: box.get(5),
child: Text(
box.get(5),
),
onTap: () {
translate.text = box.get(5);
},)
], onChanged: (value) {
box.add(keys);
},
)
],
),
color: Colors.green[100]),
),
RaisedButton(onPressed: () {
Translate();
},
child: Text('translate')),
Expanded(
child: Container(
width: MediaQuery
.of(context)
.size
.width,
height: MediaQuery
.of(context)
.size
.height * 0.6,
color: Colors.brown[500],
child: Column(
children: [
Row(
children: [
Padding(
padding: EdgeInsets.all(8.0),
child:
Text("Length = $charLength",
style: TextStyle(fontSize: 20))
),
MaterialButton(onPressed: () {},
child: Icon(Icons.clear)),
MaterialButton(onPressed: () {},
child: Icon(Icons.copy))
]
),
Text(translateoutput,
style: TextStyle(
fontFamily: 'Baybayin'
))
],
),
),
)
]
)
);
}
void Translate() {
// int chareven = charLength * even;
// setState(() {
//
// print(chareven);
//
// if(charLength == even){
// translate.text.split("");
// }
//
//
// if (translate.text == null) {
// translateoutput= "null";
// }
// else
// translateoutput = mydata[0][translate.text];
// print(translateoutput);
// });
// if (translate.text != mydata[0][translate.text]) {
// translate.text = translate.text;
//
// }
// else{
// translate.text = mydata[0][translate.text];
// }
// Queue.from(letters);
// print(letters);
setState(() {
if (translateoutput != mydata[0][translate.text]) {
translateoutput = translate.text;
}
else {
translateoutput = mydata[0][translate.text];
}
});
putdata();
print(box.get(keys));
keys++;
box.add(translate.text);
}
}