在Dart中使用json_serializable访问json中的嵌套对象

dependencies:
  json_annotation: ^4.0.0
  json_serializable: ^4.1.0
dev_dependencies:
  build_runner: ^2.1.0

{
  "name": "John",
  "age": 25,
  "address": {
    "street": "123 Main St",
    "city": "New York"
  }
}

import 'package:json_annotation/json_annotation.dart';

part 'person.g.dart';

@JsonSerializable()
class Person {
  String name;
  int age;
  Address address;

  Person({this.name, this.age, this.address});

  factory Person.fromJson(Map<String, dynamic> json) => _$PersonFromJson(json);
  Map<String, dynamic> toJson() => _$PersonToJson(this);
}

@JsonSerializable()
class Address {
  String street;
  String city;

  Address({this.street, this.city});

  factory Address.fromJson(Map<String, dynamic> json) => _$AddressFromJson(json);
  Map<String, dynamic> toJson() => _$AddressToJson(this);
}

flutter pub run build_runner build

String jsonString = '{"name": "John", "age": 25, "address": {"street": "123 Main St", "city": "New York"}}';

import 'dart:convert';

void main() {
  String jsonString = '{"name": "John", "age": 25, "address": {"street": "123 Main St", "city": "New York"}}';
  Map<String, dynamic> json = jsonDecode(jsonString);
  Person person = Person.fromJson(json);
  
  print(person.name); // 输出: John
  print(person.age); // 输出: 25
  print(person.address.street); // 输出: 123 Main St
  print(person.address.city); // 输出: New York
}