Flutter Json 编码列表

Question

如何将列表编码为 json？

这是我的 Json 课程。

class Players{
  List<Player> players;

  Players({this.players});

  factory Players.fromJson(List<dynamic> parsedJson){

    List<Player> players = List<Player>();
    players = parsedJson.map((i)=>Player.fromJson(i)).toList();

    return Players(
      players: players,
    );
  }
}

class Player{
  final String name;
  final String imagePath;
  final int totalGames;
  final int points;

  Player({this.name,this.imagePath, this.totalGames, this.points});

  factory Player.fromJson(Map<String, dynamic> json){

    return Player(
      name: json['name'],
      imagePath: json['imagePath'],
      totalGames: json['totalGames'],
      points: json['points'],
    );
  }
}

我设法用 fromJson 解码，结果在 List 中。现在我有另一个玩家要添加 json 并想将列表编码为 json，不知道怎么做。结果总是失败。

var json = jsonDecode(data);
List<Player> players = Players.fromJson(json).players;
Player newPlayer = Player(name: _textEditing.text,imagePath: _imagePath,totalGames: 0,points: 0);
players.add(newPlayer);
String encode = jsonEncode(players.players);

我需要在播放器或播放器上添加什么？

Answer 1

将toJson 方法添加到您的Player 类中：

Map<String, dynamic> toJson(){
  return {
    "name": this.name,
    "imagePath": this.imagePath,
    "totalGames": this.totalGames,
    "points": this.points
  };
}

那你可以在玩家名单上拨打jsonEncode：

String encoded = jsonEncode(players) // this will automatically call toJson on each player

Answer 2

添加类：

Map<String,dynamic> toJson(){
    return {
        "name": this.name,
        "imagePath": this.imagePath,
        "totalGames": this.totalGames,
        "points": this.points
    };
  }

然后打电话

String json = jsonEncode(players.map((i) => i.toJson()).toList()).toString();

Answer 3

List jsonList = players.map((player) => player.toJson()).toList();
print("jsonList: ${jsonList}");