C#调用扩展类的构造函数

Question

比如说我有以下课程:

    class SuperModel
{
    private OracleProvider database;
    private SqlTemplates template;
    public SuperModel()
    {
        this.database = new OracleProvider();
        this.template = new SqlTemplates(database);
    }

    protected SqlTemplates getTemplate()
    {
        return this.template;
    }
}

现在我有以下课程扩展上述内容:

    class Henvendelser : SuperModel
{
    public Henvendelser()
    {

    }

    public ArrayList getQueue(DateTime start, DateTime end)
    {
        String sql =
                "SELECT                                                                     " +
                "   TIDSPUNKT,                                                              " +
                "   NVL(QUEUE,' ') AS QUEUE,                                                " +
                "   NVL(SUM(ANTAL_KALD),0) AS CALLS,                                        " +
                "   NVL(SUM(ANTAL_BESVARET),0) AS ANSWERED_CALLS,                           " +
                "   NVL(SUM(BESVARET_25_SEK),0) AS ANSWERED_CALLS_25_SEC,                   " +
                "   NVL(SUM(INTERN_KALD),0) AS INTERNAL_CALLS                               " +
                "FROM                                                                       " +
                "   KS_DRIFT.PERO_NKM_KØ_OVERSIGT                                           " +
                "WHERE                                                                      " +
                "   TIDSPUNKT >= '" + start+ "' AND                                         " +
                "   TIDSPUNKT <= '" + end + "' AND                                          " +
                "   TO_CHAR(TIDSPUNKT,'DY') NOT IN ('AB')                                   " +
                "GROUP BY                                                                   " +
                "   QUEUE                                                                   " +
                "ORDER BY                                                                   " +
                "   TIDSPUNKT                                                               ";

        ArrayList result = this.getTemplate().template(sql, SqlTemplates.READ_FROM_QUERY);
        return result;
   }
}

是SuperModel自动调用的构造函数还是必须执行某些操作才能确保调用它？

Answer 1

在您的特定代码中,它是隐式调用的.要明确调用它,您需要使用base关键字.

请参阅:使用构造函数C#

在派生类中,如果未使用base关键字显式调用基类构造函数,则会隐式调用默认构造函数(如果有).

所以你的构造函数在派生类中:

public Henvendelser()

等于

public Henvendelser() :base()

您的代码中的其他一些小观察:

1. 用List<T>而不是ArrayList
2. 将参数与查询一起使用而不是字符串连接.请参阅Sql Injection