將數據傳遞給另一個活動

Question

所以我試圖從一個活動傳遞另一個數據，這樣做有一些困難。

這是代碼：

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); 
} 

我現在該如何獲得新的活動的數據？我試過這個，但它不起作用

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

任何想法，我怎麼能做到這一點？

檢索列表：

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

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

這紅色下劃線「數據」，所以我敢肯定有一些錯誤「數據」？

Answer 1

問題在於，當您開始新活動時，您正在創建新的意向。試試這個：

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); 
} 

在其他活動：

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