將多個對象傳遞給另一個活動

Question

我正在嘗試創建一個非常基本的應用程序，該應用程序基本上可以跟蹤4個在現實生活中玩紙牌游戲的玩家的得分。 我的想法是為每個玩家創建一個“玩家”類的實例，目前該實例僅包含變量“名稱”和“分數”。 我遵循了本文的說明（ http://sohailaziz05.blogspot.de/2012/04/passing-custom-objects-between-android.html ），並在“玩家”類中實現了Parcelable：

public class Player implements Parcelable {
    private String name;
    private int score;

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

    public String getPlayerName() {
        return name;
    }

    public int getPlayerScore() {
        return score;
    }

    public Player(Parcel in) {
        String[] data = new String[2];

        in.readStringArray(data);
        this.name = data[0];
        this.score = Integer.parseInt(data[1]);

    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {

        dest.writeStringArray(new String[]{this.name, String.valueOf(this.score)});
    }

    public static final Parcelable.Creator<Player> CREATOR = new Parcelable.Creator<Player>() {

        @Override
        public Player createFromParcel(Parcel source) {
            return new Player(source);  //using parcelable constructor
        }

        @Override
        public Player[] newArray(int size) {
            return new Player[size];
        }
    };

}

這是第一個活動的代碼（我在這里僅創建一個玩家，理想情況下應為4個或更多）：

public class CreatePlayersScreen extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_create_players_screen);
    }

    public void startGame(View view) {

        EditText editText1 = (EditText) findViewById(R.id.editText1);
        String namePlayer1 = editText1.getText().toString();
        int scorePlayer1=0;
        Player player1 = new Player(namePlayer1, scorePlayer1);

        Intent intent=new Intent(this,ScoreScreen.class);
        intent.putExtra("EXTRA_PLAYER_1",player1);

        startActivity(intent);
    }    
}

當我在第一個活動中按下按鈕時，將觸發“ startGame”，並且應該在第二個活動中顯示玩家名稱和分數：

public class ScoreScreen extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_score_screen);

        Player player1= getIntent().getParcelableExtra("EXTRA_PLAYER_1");

        String namePlayer1 = player1.getPlayerName();
        TextView textView1 = (TextView) findViewById(R.id.textView1);
        textView1.setText(namePlayer1);

        int scorePlayer1 = player1.getPlayerScore();
        TextView textView5 = (TextView) findViewById(R.id.textView5);
        textView5.setText(scorePlayer1);
    }
}

因此，當我運行此命令時，按下按鈕從第一個活動轉到第二個活動，就會在模擬器中收到以下錯誤消息： 游戲已停止再次打開應用程序

怎么了？ 可打包是正確的方法還是我應該使用可序列化的？ 我如何不僅可以將1個對象還可以將4個對象傳遞給第二個主動性？

非常感謝您的幫助，我真的很困在這里...謝謝！

Answer 1

這就是我通常的做法。

public void startGame(View view) {
    EditText editText1 = (EditText) findViewById(R.id.editText1);
    String namePlayer1 = editText1.getText().toString();
    int scorePlayer1 = 0;
    Player player1 = new Player(namePlayer1, scorePlayer1);
    EditText editText2 = (EditText) findViewById(R.id.editText2);
    String namePlayer2 = editText2.getText().toString();
    int scorePlayer2 = 0;
    Player player2 = new Player(namePlayer2, scorePlayer2);

    Intent intent = new Intent(this, ScoreScreen.class);
    Bundle bundle = new Bundle();
    bundle.putParcelable("EXTRA_PLAYER_1", player1);
    bundle.putParcelable("EXTRA_PLAYER_2", player2);
    intent.putExtras(bundle);
    startActivity(intent);
}


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    ...
    Player player1;
    Player player2;
    if (getIntent().getExtras() != null) {
        player1 = getIntent().getExtras().getParcelable("EXTRA_PLAYER_1");
        player2 = getIntent().getExtras().getParcelable("EXTRA_PLAYER_2");
    }
}