传递数据到另一个activity

Question

需要在activity之间传递数据，遇到一些困难。

代码：

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中如何得到数据？我试过：

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

检索列表:

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

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

给data加了红下划线。不知道是什么错误。

Answer 1

因为你每次开始activity都创建了一个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);
}

在另一个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");
}