java - 数组未在 Java/Android 中正确插入数据

Question

我有一个方法:

 public double getCombinedAprThisMonth() {
    Cursor c = database.rawQuery("SELECT *  FROM debt;", null);
    double totalMonthlyFee = 0;
    double SingleAprRate = 0;
    double[] storeFees;
    int rows = c.getCount();
    storeFees = new double[c.getCount()];

    for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) {
        for (int i = 0; i < rows; i++) {
            String BalColumn = c.getString(c
                    .getColumnIndex("debt_total"));
            String AprColumn = c.getString(c.getColumnIndex("apr"));
            double aprColumn = Double.valueOf(BalColumn);
            double balColumn = Double.valueOf(AprColumn);

            SingleAprRate = (((aprColumn / 100) / 12) * balColumn);
            storeFees[i++] = SingleAprRate; 

        }

    }
    for(double i : storeFees) {
        totalMonthlyFee += i;
    }

    c.close();
    return totalMonthlyFee;
}

有三个记录，所以应该发生三个循环。totalMonthlyFee 返回为 90。但是，数据为 8.33、45 和 45。我正在尝试计算它们的总和(98.33 应该是正确的，但我得到的是 90？)。有人看到这里有什么问题吗？

Answer 1

再三考虑，如果我理解您在做什么，我认为您根本不需要内部循环。也许试试这个...

int j = 0;
for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) {
        String BalColumn = c.getString(c
                .getColumnIndex("debt_total"));
        String AprColumn = c.getString(c.getColumnIndex("apr"));
        double aprColumn = Double.valueOf(BalColumn);
        double balColumn = Double.valueOf(AprColumn);

        SingleAprRate = (((aprColumn / 100) / 12) * balColumn);
        storeFees[j++] = SingleAprRate; 

    }