Question

我正在尝试在我的Activity中获得2个不同的ListView，以填充数据库内容onCreate。自从我添加代码以来，我现在因为标题中提到的错误而接近强制。

我不知道为什么会这样。

下面是代码：

    currentList = (ListView)findViewById(R.id.list_current_day);
    cursor = datasource.fetchCurrentLogs(dayExerciseDataID);
    to = new int[] { R.id.listitem_log_reps, R.id.listitem_log_weight };
    dataAdapterCurrent = new SimpleCursorAdapter(this, R.layout.listitem_log, cursor, columns, to, 0);
    currentList.setAdapter(dataAdapterCurrent);

    previousList = (ListView)findViewById(R.id.list_previous_day);
    cursor = datasource.fetchPreviousLogs(dayExerciseDataID);
    to = new int[] { R.id.listitem_log_reps, R.id.listitem_log_weight };
    dataAdapterPrevious = new SimpleCursorAdapter(this, R.layout.listitem_log, cursor, columns, to, 0);
    previousList.setAdapter(dataAdapterPrevious);

以下是数据库的结构和功能：

public Cursor fetchCurrentLogs(long dayExerciseDataID) {
    // where day = today
    Cursor cursor = database.rawQuery("select " + MySQLiteHelper.COLUMN_ID + "," + MySQLiteHelper.COLUMN_REPS + ", " + MySQLiteHelper.COLUMN_WEIGHT + " " +
            "from " + MySQLiteHelper.TABLE_LOGS + " " +
            "where " + MySQLiteHelper.COLUMN_ID_DAY_EXERCISE + " = '" + dayExerciseDataID + "'", null);
    if (cursor != null) { cursor.moveToFirst(); }
    return cursor;
}

public Cursor fetchPreviousLogs(long dayExerciseDataID) {
    // where day = closest day from today
    Cursor cursor = database.rawQuery("select " + MySQLiteHelper.COLUMN_ID + "," + MySQLiteHelper.COLUMN_REPS + ", " + MySQLiteHelper.COLUMN_WEIGHT + " " +
            "from " + MySQLiteHelper.TABLE_LOGS + " " +
            "where " + MySQLiteHelper.COLUMN_ID_DAY_EXERCISE + " = '" + dayExerciseDataID + "'", null);
    if (cursor != null) { cursor.moveToFirst(); }
    return cursor;
}

    database.execSQL("create table " + TABLE_LOGS + " (" 
            + COLUMN_ID + " integer primary key autoincrement," 
            + COLUMN_ID_DAY_EXERCISE + " integer not null,"
            + COLUMN_REPS + " integer not null,"
            + COLUMN_WEIGHT + " real not null,"
            + COLUMN_1RM + " real not null,"
            + COLUMN_DATE + " integer not null"
            + ")");

有人能说清楚为什么会这样吗？如果我错过了任何重要的代码，请告诉我，我会更新问题。

Answer 1

尝试对两个列表使用不同的cursor实例。

currentList = (ListView)findViewById(R.id.list_current_day);
cursor1 = datasource.fetchCurrentLogs(dayExerciseDataID);

和

previousList = (ListView)findViewById(R.id.list_previous_day);
cursor2 = datasource.fetchPreviousLogs(dayExerciseDataID);

Answer 2

你必须以这种方式使用SimpleCursorAdapter

dataAdapterPrevious = new SimpleCursorAdapter(this, R.layout.listitem_log, cursor, columns, to);

而不是

 dataAdapterPrevious = new SimpleCursorAdapter(this, R.layout.listitem_log, cursor, columns, to, 0);

Android CursorIndexOutOfBoundsException请求索引0，大小为0

2 个答案: