Android共享首选项TinyDB putListObject函数 [英] Android Shared Preference TinyDB putListObject frunction

问题描述

我正在尝试使用TinyDB的 putListObject 函数将对象列表保存到共享首选项中，但是却出现了第二参数类型错误错误.我可以很好地使用 putObject 函数，该错误仅在使用 putListObject 函数时出现.

I'm trying to save an object list to the Shared Preferences using TinyDB's putListObject function, but I'm getting a Wrong 2nd argument type error. I can use the putObject function just fine, the error only appears when I use the putListObject function.

玩家职业:

public class Player {

    private String name = "";
    private int score = 0;

    public Player(String name, int score) {
        this.name = name;
        this.score = score;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getScore() {
        return score;
    }

    public void setScore(int score) {
        this.score = score;
    }
}

putListObject函数:

putListObject function:

 public void putListObject(String key, ArrayList<Object> objArray){
        checkForNullKey(key);
        Gson gson = new Gson();
        ArrayList<String> objStrings = new ArrayList<String>();
        for(Object obj : objArray){
            objStrings.add(gson.toJson(obj));
        }
        putListString(key, objStrings);
    }

我如何使用该功能:

ArrayList<Player> playerList = new ArrayList<Player>();

TinyDB tinydb = new TinyDB(this);
tinydb.putListObject("players", playerList);

我得到的错误:

TinyDB中的

putListObject(字符串java.util.ArrayList< java.lang.Object>)不能应用于(Stringjava.util.ArrayList< com.example.package.Player>)

putListObject (String java.util.ArrayList<java.lang.Object>) in TinyDB cannot be applied to (String java.util.ArrayList<com.example.package.Player>)

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我们将不胜感激！

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Help would be much appreciated!

推荐答案

尽管 Player 的任何实例都是 Object ，是 ArrayList 播放器与对象的 ArrayList 不同.将您的方法签名更改为:

Although any instance of Player is an Object, an ArrayList of Players is not the same as an ArrayList of Objects. Change your method signature to :

putListObject(String key, ArrayList<Player> objArray)

和for循环至:

for(Player player : objArray){
   objStrings.add(gson.toJson(player));
}

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