IllegalArgumentException：无效的列-SEARCHVIEW

Question

我想在使用SearchView时从数据库表中获取建议。

我收到IllegalArgumentException：无效的列 （ 列的名称）

    private static final HashMap<String, String> mColumnMap = buildColumnMap();

    //Build a map for all columns that may be requested, which will be given to SQLiteQueryBuilder.
    //This allow ContentProvider to request columns without the need to know real column names and
    //create the alias itself
    private static HashMap<String, String> buildColumnMap() {
        HashMap<String, String> map = new HashMap<String, String>();

        map.put(SearchManager.SUGGEST_COLUMN_TEXT_1, "rowid AS " +
                CookingContract.FoodEntry.COLUMN_NAME);
        map.put(SearchManager.SUGGEST_COLUMN_TEXT_2, "rowid AS " +
                CookingContract.FoodEntry.COLUMN_DESCRIPTION);
        map.put(SearchManager.SUGGEST_COLUMN_INTENT_DATA_ID, "rowid AS " + CookingContract.FoodEntry._ID);


        return map;
    }


    //Return a Cursor over all words that match the given query
    public Cursor getWordMatches(String query, String[] columns) {
        String selection = CookingContract.FoodEntry.COLUMN_NAME + " LIKE ?";
        String[] selectionArgs = new String[]{"%" + query + "%"};

        return query(selection, selectionArgs, columns);
    }

    //The SQLiteBuilder provides a map for all possible columns requested to actual columns in the
    //DB, creating a simple column alias mechanism by which the ContentProvider doesn't need to know
    //the real column names
    private Cursor query(String selection, String[] selectionArgs, String[] columns) {
        SQLiteQueryBuilder builder = new SQLiteQueryBuilder();
        builder.setTables(CookingContract.FoodEntry.TABLE_NAME);
        builder.setProjectionMap(mColumnMap);


        Cursor cursor = builder.query(getReadableDatabase(),
                columns, selection, selectionArgs, null, null, null);

        if (cursor == null) {
            return null;
        } else if (!cursor.moveToFirst()) {
            cursor.close();
            return null;
        }
        return cursor;
    }
}

这是我的ContentProvider代码的一部分

public Cursor query(Uri uri, String[] projection, String selection,
                    String[] selectionArgs, String sortOrder) {
    Cursor retCursor;
    switch (sUriMatcher.match(uri)) {

        case SEARCH_SUGGEST:

            if (selectionArgs == null) {
                throw new IllegalArgumentException(
                        "selectionArgs must be provided for the Uri: +"uri");
            }
            return getSuggestions(selectionArgs[0]);

        default:
            throw new UnsupportedOperationException("Unknown uri: " + uri);
    }

    retCursor.setNotificationUri(getContext().getContentResolver(), uri);
    return retCursor;
}

private Cursor getSuggestions(String query) {
    query = query.toLowerCase();
    String[] columns = new String[]{
           CookingContract.FoodEntry._ID,
           CookingContract.FoodEntry.COLUMN_NAME,
           CookingContract.FoodEntry.COLUMN_DESCRIPTION,

    };
    return cookingDBHelper.getWordMatches(query, columns);
}

使用setProjectionMap，我应该能够告诉Android我的列名是什么，并使用它遵守SearchManager约束...我该怎么办？

Answer 1

我认为您的投影图（mColumnMap）不正确，您所拥有的是：

map.put(SearchManager.SUGGEST_COLUMN_TEXT_1, "rowid AS " +
            CookingContract.FoodEntry.COLUMN_NAME);
map.put(SearchManager.SUGGEST_COLUMN_TEXT_2, "rowid AS " +
            CookingContract.FoodEntry.COLUMN_DESCRIPTION);
map.put(SearchManager.SUGGEST_COLUMN_INTENT_DATA_ID, "rowid AS " + 
            CookingContract.FoodEntry._ID);

这意味着您将通过以下方式映射列：

SUGGEST_COLUMN_NAME -> rowid AS COLUMN_NAME
SUGGEST_COLUMN_TEXT_2 -> rowid AS COLUMN_DESCRIPTION
SUGGEST_COLUMN_INTENT_DATA_ID -> rowid AS _ID

当查询生成器使用您的地图时，它将列名重命名为在地图上作为值指定的列名，但是根据您在地图上作为键提供的列，当前查询的任何列都不会正确映射。

String[] columns = new String[]{
       CookingContract.FoodEntry._ID,
       CookingContract.FoodEntry.COLUMN_NAME,
       CookingContract.FoodEntry.COLUMN_DESCRIPTION,

};

上面的列无法正确映射，因为它们都不是投影​​地图上的键。

关于这个问题的一些例子可以在地图投影上找到。

考虑到有关自定义建议的指南，要返回的游标应至少包含两列： _ID和SUGGEST_COLUMN_TEXT_1 ，因此，我建议您将地图更改为以下内容：

map.put(CookingContract.FoodEntry._ID, 
            CookingContract.FoodEntry._ID + " as " + SearchManager._ID);
map.put(CookingContract.FoodEntry.COLUMN_NAME,
            CookingContract.FoodEntry.COLUMN_NAME + " as " + SearchManager.SUGGEST_COLUMN_TEXT_1);
map.put(CookingContract.FoodEntry.COLUMN_DESCRIPTION,
            CookingContract.FoodEntry.COLUMN_DESCRIPTION + " as " + SearchManager.SUGGEST_COLUMN_TEXT_2);

使用此映射，将以以下方式映射您提供的列：

FoodEntry._ID -> _ID
FoodEntry.COLUMN_NAME -> FoodEntry.COLUMN_NAME as SUGGEST_COLUMN_TEXT_1
FoodEntry.COLUMN_DESCRIPTION -> FoodEntry.COLUMN_DESCRIPTION as SUGGEST_COLUMN_TEXT_2

注意，我省略了SUGGEST_COLUMN_INTENT_DATA_ID列，因为我不知道您要使用哪一列查询数据库中的一条记录，它可以是rowId或_ID ，您可以根据需要调整投影图。

另外，请确保您在清单中配置了android:searchSuggestIntentAction以便正确处理操作。

希望这使对异常的思路更加清晰。