flutter json_serializable使用

1，添加依赖

dependencies:
   json_annotation: ^2.4.0

dev_dependencies:
  build_runner: ^1.0.0
  json_serializable: ^3.0.0

2，根据接口返回json创建实体类

class HomeEntity {
	String authToken;
	bool showTask;
	int pendingCount;
	int waitCheckCount;
	int checkingCount;
	int checkfailCount;

	HomeEntity({this.authToken, this.pendingCount,this.checkfailCount,this.checkingCount,this.showTask,this.waitCheckCount});
}

3,关联实体类文件

part 'home_entity.g.dart';
@JsonSerializable(nullable: false)
class HomeEntity {
	String authToken;
	bool showTask;
	int pendingCount;
	int waitCheckCount;
	int checkingCount;
	int checkfailCount;

	HomeEntity({this.authToken, this.pendingCount,this.checkfailCount,this.checkingCount,this.showTask,this.waitCheckCount});
}

声明part 部分，当前项目目录下执行命令 flutter packages pub run build_runner build
Successed 后会发现dart文件目录下会生成”home_entity.g.dart“文件，这个”home_entity.g.dart“就是build_runner根据JsonSerializable生成的json解析文件，文件内容如下：

// GENERATED CODE - DO NOT MODIFY BY HAND

part of 'home_entity.dart';

// **************************************************************************
// JsonSerializableGenerator
// **************************************************************************

HomeEntity _$HomeEntityFromJson(Map json) {
  return HomeEntity(
      authToken: json['authToken'] as String,
      pendingCount: json['pendingCount'] as int,
      checkfailCount: json['checkfailCount'] as int,
      checkingCount: json['checkingCount'] as int,
      showTask: json['showTask'] as bool,
      waitCheckCount: json['waitCheckCount'] as int);
}

Map _$HomeEntityToJson(HomeEntity instance) =>
    {
      'authToken': instance.authToken,
      'showTask': instance.showTask,
      'pendingCount': instance.pendingCount,
      'waitCheckCount': instance.waitCheckCount,
      'checkingCount': instance.checkingCount,
      'checkfailCount': instance.checkfailCount
    };

• _$HomeEntityFromJson:它接收了一个map：Map，并将这个Map里的值映射为我们所需要的实体类对象。我们就可以使用这个方法，将存有json数据的map转化为我们需要的实体类对象。
• _$HomeEntityToJson:将调用此方法的对象直接根据字段映射成Map。

4，实体类中添加fromJson 和 toJson方法

import 'package:json_annotation/json_annotation.dart';

part 'home_entity.g.dart';
@JsonSerializable(nullable: false)
class HomeEntity {
	String authToken;
	bool showTask;
	int pendingCount;
	int waitCheckCount;
	int checkingCount;
	int checkfailCount;

	HomeEntity({this.authToken, this.pendingCount,this.checkfailCount,this.checkingCount,this.showTask,this.waitCheckCount});

 factory HomeEntity.fromJson(Map json) => _$HomeEntityFromJson(json);

	Map toJson() => _$HomeEntityToJson(this);
}