常见数据转化

Flutter map与json的数据的区别

 //map (ios中称为字典)
final chat = {
     "name":"张三",
    "message":"近期去哪玩？",
} ;

 //map转json
 final chatjson = json.encode(chat);
 print(chat);
 print(chatjson);
//打印输出结果:
flutter: {name: 张三, message: 近期去哪玩？}
flutter: {"name":"张三","message":"近期去哪玩？"}

//json转map
final newchat = json.decode(chatjson);
print(newchat);
print(newchat["name"]);
//打印输出结果:
flutter: {name: 张三, message: 近期去哪玩？}
flutter: 张三

从上面的例子可以看出,map是取消引号的字符串.

map与model模型的转化

class ChatModel{
  final String name;
  final String message;
  const  ChatModel(this.name, this.message);
    
  //工厂模式
  factory ChatModel.fromJson(Map json){
    return ChatModel(json["name"], json["message"]);
  }
}

final model = ChatModel.fromJson(newchat);
print("name:${model.name}   message:${model.message}");

//打印结果:
flutter: name:张三   message:近期去哪玩？