将数据传递给另一个活动

Question

所以我试图从一个活动中传递一些数据，但我在这样做时遇到了一些困难。

这是代码：

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);
}

我现在如何获取新活动中的数据？我试过了，但它不起作用

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

有什么想法我还能做到这一点吗？

检索列表：

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

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

红色下划线“数据”，所以我很确定“数据”有问题？

Answer 1

问题在于，当您开始新活动时，您正在创建一个新意图。试试这个：

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);
}

关于其他活动：

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