我在尝试使用 Dart/Flutter 中的 json_serializable 包对继承的类进行反序列化时遇到问题。这是代码示例：
@JsonSerializable(explicitToJson: true)
class Document {
String id = UniqueKey().toString();
String name='';
List<Component> components=[]; //list of Components
Document({required this.components}):super();
Document.empty();
factory Document.fromJson(Map<String, dynamic> json) =>_$DocumentFromJson(json);
Map<String, dynamic> toJson() => _$DocumentToJson(this);
}
@JsonSerializable()
class Component { //Component Base Class
String id = UniqueKey().toString();
String name='';
Component();
factory Component.fromJson(Map<String, dynamic> json) =>_$ComponentFromJson(json);
Map<String, dynamic> toJson() => _$ComponentToJson(this);
}
@JsonSerializable()
class TextComponent extends Component{ //inherited from Component
String text='';
TextComponent():super();
TextComponent.text({required this.text}):super();
factory TextComponent.fromJson(Map<String, dynamic> json) =>_$TextComponentFromJson(json);
@override Map<String, dynamic> toJson() => _$TextComponentToJson(this);
}
这是测试：
void main() {
//creating json from object
Document d = Document(components:[TextComponent.text(text: 'text')] );
print(d.components[0].runtimeType); //-type is : TextComponent
var json = d.toJson();
//create object from json
var newDoc = Document.fromJson(json);
print(newDoc.components[0].runtimeType); //-type is : Component which is the base class
}
反序列化后继承的类被向下转换为基类，但我需要继承的类。