java-傳遞數據到另一個activity

傳遞數據到另一個activity

需要在activity之間傳遞數據，遇到一些困難。

代碼：

private TextView createNewTextView (String text){
    final LayoutParams lparams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
    final TextView newTextView = new TextView(this);
    ArrayList<String> players = new ArrayList<String>();
    Intent zacniIgro = getIntent();

    newTextView.setLayoutParams(lparams);
    newTextView.setText(text);
    players.add(text);
    zacniIgro.putStringArrayListExtra("players", players);
    return newTextView;
}

public void zacniIgro (View v){
    Intent zacniIgro = new Intent (getApplicationContext(), Igra.class);
    startActivity(zacniIgro);
}

在新的activity中如何得到數據？我試過：

ArrayList<String> players = data.getStringArrayListExtra("players");

檢索列表:

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

    ArrayList<String> players = data.getStringArrayListExtra("players");
}

給data加了紅下劃線。不知道是什麼錯誤。

最佳回答：

因為你每次開始activity都創建了一個intent。

ArrayList<String> players = new ArrayList<String>(); //declare it outside of the function

private TextView createNewTextView (String text){
    final LayoutParams lparams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
    final TextView newTextView = new TextView(this);

    newTextView.setLayoutParams(lparams);
    newTextView.setText(text);
    players.add(text);
    return newTextView;
}

public void zacniIgro (View v){
    Intent zacniIgro = new Intent (getApplicationContext(), Igra.class);
    zacniIgro.putStringArrayListExtra("players", players);
    startActivity(zacniIgro);
}

在另一個activity中:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_igra);
    Intent data = getIntent();
    ArrayList<String> players = data.getStringArrayListExtra("players");
}