您好，我使用 Hive 来存储我的应用程序的数据，当我运行代码时，我可以添加主类别，并且可以为每个类别添加子类别。当我关闭应用程序并再次打开时，我可以添加主类别，但是当我尝试为现有主类别添加子类别时，我无法添加新的子类别并且我遇到错误“未处理的异常：不支持的操作：无法添加到固定长度列表'，我该如何解决我被卡住了，请帮助我。
这是我的 categoryModel 和 subCategoryMoldel 类和子类别屏幕。谢谢你的帮助。
part 'categoryModel.g.dart';
@HiveType(typeId : 0)
class CategoryModel extends HiveObject{
CategoryModel(
{ this.categoryId,
this.categoryImagePath,
this.categoryName,
this.categoryColor,
this.subCategoryModels});
@HiveField(0)
final int categoryColor;
@HiveField(1)
List <SubCategoryModel> subCategoryModels;
@HiveField(2)
int categoryId;
@HiveField(3)
String categoryImagePath;
@HiveField(4)
String categoryName;
}
// GENERATED CODE - DO NOT MODIFY BY HAND
part of 'categoryModel.dart';
// **************************************************************************
// TypeAdapterGenerator
// **************************************************************************
class CategoryModelAdapter extends TypeAdapter<CategoryModel> {
@override
final int typeId = 0;
@override
CategoryModel read(BinaryReader reader) {
final numOfFields = reader.readByte();
final fields = <int, dynamic>{
for (int i = 0; i < numOfFields; i++) reader.readByte(): reader.read(),
};
return CategoryModel(
categoryId: fields[2] as int,
categoryImagePath: fields[3] as String,
categoryName: fields[4] as String,
categoryColor: fields[0] as int,
subCategoryModels: (fields[1] as List)?.cast<SubCategoryModel>(),
);
}
@override
void write(BinaryWriter writer, CategoryModel obj) {
writer
..writeByte(5)
..writeByte(0)
..write(obj.categoryColor)
..writeByte(1)
..write(obj.subCategoryModels)
..writeByte(2)
..write(obj.categoryId)
..writeByte(3)
..write(obj.categoryImagePath)
..writeByte(4)
..write(obj.categoryName);
}
@override
int get hashCode => typeId.hashCode;
@override
bool operator ==(Object other) =>
identical(this, other) ||
other is CategoryModelAdapter &&
runtimeType == other.runtimeType &&
typeId == other.typeId;
}
part 'subCategoryModel.g.dart';
@HiveType(typeId : 1)
class SubCategoryModel extends HiveObject{
SubCategoryModel({
this.subCategoryId,
this.subCategoryCardId,
this.subCategoryImagePath,
this.subCategoryName,
this.categoryColor,
this.recipeId,
this.ingredients,
this.recipePhotoDir,
this.recordedVoiceDir});
@HiveField(0)
final int categoryColor;
@HiveField(1)
final double recipeId;
@HiveField(2)
bool isCompleted;
@HiveField(3)
int subCategoryId;
@HiveField(4)
String subCategoryImagePath;
@HiveField(5)
String subCategoryName;
@HiveField(6)
List <Ingredient> ingredients;
@HiveField(7)
String recipePhotoDir;
@HiveField(8)
String recordedVoiceDir;
@HiveField(9)
int subCategoryCardId;
}
// GENERATED CODE - DO NOT MODIFY BY HAND
part of 'subCategoryModel.dart';
// **************************************************************************
// TypeAdapterGenerator
// **************************************************************************
class SubCategoryModelAdapter extends TypeAdapter<SubCategoryModel> {
@override
final int typeId = 1;
@override
SubCategoryModel read(BinaryReader reader) {
final numOfFields = reader.readByte();
final fields = <int, dynamic>{
for (int i = 0; i < numOfFields; i++) reader.readByte(): reader.read(),
};
print(fields[3]);
print(fields[0]);
return SubCategoryModel(
subCategoryId: fields[3] as int,
subCategoryImagePath: fields[4] as String,
subCategoryName: fields[5] as String,
categoryColor: fields[0] as int,
recipeId: fields[1] as double,
ingredients: (fields[6] as List)?.cast<Ingredient>(),
recipePhotoDir: fields[7] as String,
recordedVoiceDir: fields[8] as String,
subCategoryCardId:fields[9] as int ,
)..isCompleted = fields[2] as bool;
}
@override
void write(BinaryWriter writer, SubCategoryModel obj) {
writer
..writeByte(10)
..writeByte(0)
..write(obj.categoryColor)
..writeByte(1)
..write(obj.recipeId)
..writeByte(2)
..write(obj.isCompleted)
..writeByte(3)
..write(obj.subCategoryId)
..writeByte(4)
..write(obj.subCategoryImagePath)
..writeByte(5)
..write(obj.subCategoryName)
..writeByte(6)
..write(obj.ingredients)
..writeByte(7)
..write(obj.recipePhotoDir)
..writeByte(8)
..write(obj.recordedVoiceDir)
..writeByte(9)
..write(obj.subCategoryCardId);
}
@override
int get hashCode => typeId.hashCode;
@override
bool operator ==(Object other) =>
identical(this, other) ||
other is SubCategoryModelAdapter &&
runtimeType == other.runtimeType &&
typeId == other.typeId;
}
class SubCategoriesScreen extends StatefulWidget {
SubCategoriesScreen({this.categoryId,this.subCategoryName, this.subCategoryImagePath});
static String id="subCategoriesScreen";
final String subCategoryName;
final String subCategoryImagePath;
final int categoryId;
Widget buildBottomSheet(BuildContext context)=>AddMenuScreen(categoryId: categoryId,buttonText: "Tarif Ekle",route: "subCategoryScreen",);
@override
_SubCategoriesScreenState createState() => _SubCategoriesScreenState();
}
class _SubCategoriesScreenState extends State<SubCategoriesScreen> {
int _flag=0;
Box<CategoryModel> _categoryModelBox;
CategoryModel _categoryModel;
SubCategoryModel _subCategoryModel;
void initState(){
super.initState();
_categoryModelBox = Hive.box<CategoryModel>("categoryModelsInBox");
_categoryModel = _categoryModelBox.getAt(widget.categoryId);
print(_categoryModel);
print(widget.subCategoryName);
print(widget.subCategoryImagePath);
print(widget.categoryId);
if(widget.categoryId!=null && widget.subCategoryImagePath!=null && widget.subCategoryName!=null){
addSubCategory();
}
}
void addSubCategory()async{
_subCategoryModel=SubCategoryModel(
subCategoryCardId: _categoryModel.subCategoryModels.length,
subCategoryId:widget.categoryId,
subCategoryImagePath: widget.subCategoryImagePath,
subCategoryName: widget.subCategoryName,
categoryColor: Color((Random().nextDouble() * 0xFFFFFF).toInt()).withOpacity(0.5).value);
print(_subCategoryModel.subCategoryImagePath);
print(_subCategoryModel.subCategoryName);
print(_subCategoryModel.subCategoryCardId);
_categoryModel.subCategoryModels.add(_subCategoryModel);
_categoryModel.save();
}
@override
Widget build(BuildContext context) {
return SafeArea(
child: Scaffold(
body: Scaffold(
appBar: AppBar(
automaticallyImplyLeading: false,
centerTitle: true,
title: BorderedText(
child:Text(
_categoryModel.categoryName,
style: TextStyle(
color: Color(0XFFFFFB00),
fontSize: 30,
fontFamily: "OpenSans"
),
),
strokeWidth: 5,
strokeColor: Colors.black,
),
elevation: 5,
backgroundColor: Color(0xFFF2C3D4).withOpacity(1),
leading: IconButton(
icon: Icon(Icons.arrow_back),
onPressed: (){
Navigator.pop(context);
},
iconSize: 40,
color: Color(0xFFA2000B),
),
actions: [
CircleAvatar(
radius: 27,
backgroundColor: Colors.transparent,
backgroundImage: AssetImage("images/cuttedlogo.PNG"),
)
],
),
body:Container(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage("images/logoBGopacity.png"),
fit: BoxFit.cover,
),
),
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: [
Expanded(
child: GridView.builder(
scrollDirection: Axis.vertical,
gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 2),
itemCount:_categoryModel.subCategoryModels.length+1,
itemBuilder: (context,index){
if(_categoryModel.subCategoryModels.length==0){
return EmptyCard(where: "subCategoryScreen",categoryId: _categoryModel.categoryId,);
}
if(_flag==1){
return EmptyCard(where: "subCategoryScreen",categoryId: _categoryModel.categoryId);
}
if(index==_categoryModel.subCategoryModels.length-1){
_flag=1;
return SubCategoryCard(subCategoryModel:_categoryModel.subCategoryModels[index]);
}
else{
return SubCategoryCard(subCategoryModel:_categoryModel.subCategoryModels[index]);
}
}
),
),
Column(
mainAxisAlignment: MainAxisAlignment.end,
crossAxisAlignment: CrossAxisAlignment.stretch,
children: [
Padding(
padding: EdgeInsets.all(10),
child: Container(
decoration: BoxDecoration(
border: Border.all(style: BorderStyle.solid),
color: kColorTheme7,
borderRadius: BorderRadius.circular(40),
),
child: TextButton(
onPressed: (){
showModalBottomSheet(
isDismissible: false,
enableDrag: false,
context: context,
builder: (BuildContext context)=> AddMenuScreen(categoryId:_categoryModel.categoryId,buttonText: "Tarif Ekle", route:"subCategoryScreen"),
);
},
child: BorderedText(
strokeWidth: 5,
strokeColor: Colors.black,
child:Text("Tarif Ekle",style: TextStyle(
color: Colors.white,
fontFamily:'OpenSans',
fontSize:30,
),
),
),
),
),
),
],
)
],
),
),
)
),
);
}
}