flutter json解析json_serializable的使用

1、添加依赖

dependencies:
  flutter:
    sdk: flutter
  cupertino_icons: ^1.0.2
  
  json_annotation: ^4.7.0

dev_dependencies:
  build_runner: ^2.2.1
  json_serializable: ^6.4.1

2、创建对象

创建对象，添加序列化注解，导入package:json_annotation/json_annotation.dart类，添加part xxx.g.dart

import 'package:json_annotation/json_annotation.dart';     //引入此类
part 'DemoModel.g.dart';      //必须添加否则无法生成对应的文件

@JsonSerializable()
class DemoModel{
  int code;
  String msg;
  dynamic data;

  DemoModel(this.code,this.msg,this.data);

  factory DemoModel.fromJson(Map<String, dynamic> json) => _$DemoModelFromJson(json);
  Map<String, dynamic> toJson()=> _$DemoModelToJson(this);
}

3、生成xxx.g.dart文件

注意：再生成文件之前必须在实体文件中添加part xxx.g.dart，否则无法生成xxx.g.d