android - ContentValues 数组中的重复 ContentValues

Question

对此有什么帮助吗，确保它很简单但看不到它。

对内容提供者 (UserDictionary) 执行 bulkInsert，但所有插入都具有相同的“单词”值。问题是 ContentValues 数组。这是我的一些测试代码:

  public void mClick(View v){

        int batchSize = 25;
        ContentValues[] mValueArray = new ContentValues[batchSize];
        List<ContentValues>mValueList = new ArrayList<ContentValues>();
        ContentValues mNewValues = new ContentValues();

        mNewValues.put(UserDictionary.Words.APP_ID, this.getPackageName());
        mNewValues.put(UserDictionary.Words.LOCALE, "en");
        mNewValues.put(UserDictionary.Words.FREQUENCY, "255");
        mNewValues.put(UserDictionary.Words.WORD, "WORD1");

        mValueList.add(mNewValues);

        mNewValues.put(UserDictionary.Words.APP_ID, this.getPackageName());
        mNewValues.put(UserDictionary.Words.LOCALE, "en");
        mNewValues.put(UserDictionary.Words.FREQUENCY, "255");
        mNewValues.put(UserDictionary.Words.WORD, "WORD2");

        mValueList.add(mNewValues);

        mValueArray = new ContentValues[mValueList.size()];
        mValueList.toArray(mValueArray); 

        Log.i(TAG,mValueList.toString());
        Log.i(TAG,mValueArray[0].toString());
        Log.i(TAG,mValueArray[1].toString());


    }

并且从log中可以看出mValueArray存在重复值。

02-22 12:33:51.060: I/log(859): [appid=dictionary word=WORD2 frequency=255 locale=en, appid=dictionary word=WORD2 frequency=255 locale=en]
02-22 12:33:51.070: I/log(859): appid=dictionary word=WORD2 frequency=255 locale=en
02-22 12:33:51.070: I/log(859): appid=dictionary word=WORD2 frequency=255 locale=en

显然，我在向数组添加值时做错了。谁能帮我？谢谢

Answer 1

您正在修改同一个对象。这应该可以正常工作:

 public void mClick(View v){

        int batchSize = 25;
        ContentValues[] mValueArray = new ContentValues[batchSize];
        List<ContentValues>mValueList = new ArrayList<ContentValues>();
        ContentValues mNewValues = new ContentValues();

        mNewValues.put(UserDictionary.Words.APP_ID, this.getPackageName());
        mNewValues.put(UserDictionary.Words.LOCALE, "en");
        mNewValues.put(UserDictionary.Words.FREQUENCY, "255");
        mNewValues.put(UserDictionary.Words.WORD, "WORD1");

        mValueList.add(mNewValues);

        mNewValues = new ContentValues();
        mNewValues.put(UserDictionary.Words.APP_ID, this.getPackageName());
        mNewValues.put(UserDictionary.Words.LOCALE, "en");
        mNewValues.put(UserDictionary.Words.FREQUENCY, "255");
        mNewValues.put(UserDictionary.Words.WORD, "WORD2");

        mValueList.add(mNewValues);

        mValueArray = new ContentValues[mValueList.size()];
        mValueList.toArray(mValueArray); 

        Log.i(TAG,mValueList.toString());
        Log.i(TAG,mValueArray[0].toString());
        Log.i(TAG,mValueArray[1].toString());


    }

关于为什么您的代码不起作用的更多解释:当您使用 add() 时，您将对象 reference(指针)保存在 < em>列表。它不复制对象。当您稍后修改同一个对象时，列表 中的引用仍然指向这个对象，因此您也在修改那个对象。您只有 2 个对同一个对象的引用。