如何將2個SharedPreferences合併爲一個？

Question

認爲我有2個sharedPreferences文件，一個是通過創建 「PreferenceManager.getDefaultSharedPreferences（...）;」 和一個通過getSharedPreferences（someString，Context.MODE_PRIVATE）」，我知道鑰匙在獨特兩者。

那麼將會將所有鍵&值從一個文件，其他？

有一種簡單的方法來移動它們呢？

我想使用類似的代碼this answer，但不會我需要考慮每個值的類型？

編輯：

這是爲了做這件事，但它是一個有點不安全的，因爲新的類型可能在將來，這意味着它不會被支持添加到SharedPreferences：

 final Editor edit = targetSharedPreferences.edit(); 
     final Map<String, ?> srcSharedPreferenceAll = srcSharedPreference.getAll(); 
     for (final Entry<String, ?> entry : srcSharedPreferenceAll.entrySet()) { 
      if (entry.getValue() instanceof Integer) 
       edit.putInt(entry.getKey(), (Integer) entry.getValue()); 
      else if (entry.getValue() instanceof Boolean) 
       edit.putBoolean(entry.getKey(), (Boolean) entry.getValue()); 
      else if (entry.getValue() instanceof Long) 
       edit.putLong(entry.getKey(), (Long) entry.getValue()); 
      else if (entry.getValue() instanceof String) 
       edit.putString(entry.getKey(), (String) entry.getValue()); 
      else if (entry.getValue() instanceof Float) 
       edit.putFloat(entry.getKey(), (Float) entry.getValue()); 
      else if (entry.getValue() instanceof Set<?>) 
       edit.putStringSet(entry.getKey(), (Set<String>) entry.getValue()); 
     } 
     edit.apply(); 
     srcSharedPreference.edit().clear().apply(); 

我已經成功地將xml標記從一個SharedPreference文件複製到另一個SharedPreference文件，但由於某種原因，它只會在下一個會話中被SharedPreference對象注意到，而不是當前的（可能會被緩存）。下面的代碼：

private static final String DST_XML_FILE = "dst"; 

    // creating the data, for reading&writing later: 
    final SharedPreferences srcSharedPreference = getSharedPreferences(String , Context.MODE_PRIVATE); 
    srcSharedPreference.edit().clear().putInt("someInt", 12).putString("someString", "hi").putBoolean("someBoolean", true).apply(); 
    final SharedPreferences targetSharedPreferences = PreferenceManager.getDefaultSharedPreferences(this); 
    targetSharedPreferences.edit().clear().putInt("someInt2", 23).putString("someString2", "hi there").putBoolean("someBoolean2", false).apply(); 

    //checking content before 
    Log.d("AppLog", "before"); 
    final Map<String, ?> src = srcSharedPreference.getAll(); 
    Log.d("AppLog", "src:" + src.size()); 
    final Map<String, ?> targetSharedPreferencesAll = targetSharedPreferences.getAll(); 
    Log.d("AppLog", "target:" + targetSharedPreferencesAll.size()); 

    // the moving of the XML tags: 
    final PackageInfo packageInfo = getPackageManager().getPackageInfo(getPackageName(), 0); 
    File dstFile = new File(packageInfo.applicationInfo.dataDir, "shared_prefs/" + (VERSION.SDK_INT >= VERSION_CODES.N ? PreferenceManager.getDefaultSharedPreferencesName(this) : getPackageName() + "_preferences") + ".xml"); 
    File srcFile = new File(packageInfo.applicationInfo.dataDir, "shared_prefs/" + SRC_XML_FILE + ".xml"); 

    DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance(); 
    Node srcNode = docFactory.newDocumentBuilder().parse(srcFile).getFirstChild(); 
    Node dstNode = docFactory.newDocumentBuilder().parse(dstFile).getFirstChild(); 
    final NodeList childNodes = srcNode.getChildNodes(); 
    for (int i = 0; i < childNodes.getLength(); ++i) { 
     final Node item = childNodes.item(i); 
     Node importedNode = dstNode.getOwnerDocument().importNode(item, true); 
     srcNode.removeChild(item); 
     dstNode.appendChild(importedNode); 
    } 
    TransformerFactory transformerFactory = TransformerFactory.newInstance(); 
    Transformer transformer = transformerFactory.newTransformer(); 
    DOMSource source = new DOMSource(dstNode); 
    StreamResult result = new StreamResult(dstFile); 
    transformer.transform(source, result); 

    //checking content after 
    Log.d("AppLog", "after"); 
    final Map<String, ?> src = srcSharedPreference.getAll(); 
    Log.d("AppLog", "src:" + src.size()); 
    final Map<String, ?> targetSharedPreferencesAll = targetSharedPreferences.getAll(); 
    Log.d("AppLog", "target:" + targetSharedPreferencesAll.size()); 

Answer 1

Map<String,?> keys = prefs.getAll(); 
for(Map.Entry<String,?> entry : keys.entrySet()){ 
     Object o = keys.get(entry); 
     if (o instanceof Boolean) 
     { 
      pref2.putBoolean(o); 
     } 
     if (o instanceof String) 
     { 
      pref2.putString(o); 
     } 
     ... 
    } 
}