Question

我正在使用C＃winforms开发一个视频租赁应用程序，并遇到了一个我似乎无法编写或找到解决方案的问题。

程序需要检查当前日期和过去的天数以及它们之间的范围。

如果当前日期小于或等于指定日期，则不会计算罚金。

否则，如果今天的日期已经超过指定的日期，它将计算罚款成本乘以它们之间经过的天数。

以下是我玩过这个想法的示例代码：

        DateTime db = DateTime.Parse(dateBeforeString);
        DateTime dt = DateTime.Now;

        var dateDiff = (dt - db);
        double totalDays = dateDiff.TotalDays;

        int totalPenalty = initialPenaltyInt*(int)Convert.ToInt64(totalDays);
        int totalCost = totalPenalty + rentalCostInt;

        if(DateTime.Now != db)
        {
            //do stuff here to:
            //check if current day is less than the one on the database
            //set total penalty to zero
        }
        else if(DateTime.Now > db)
        {
            //otherwise calculate the total penalty cost multipled by the number of days passed since a specific date
        }

Answer 1

简单，但可能有助于你进步，希望：

public class Penalties
{
    // What about this choice of "int" (vs. decimal)?
    public virtual int ComputeOverdueDaysPenalty(int penaltyPerOverdueDay, DateTime dueDate)
    {
        // Work only with year, month, day, to drop time info and ignore time zone
        dueDate = new DateTime(dueDate.Year, dueDate.Month, dueDate.Day);
        var now = DateTime.Now;
        now = new DateTime(now.Year, now.Month, now.Day);
        return now > dueDate ? (int)now.Subtract(dueDate).TotalDays * penaltyPerOverdueDay : 0;
    }
}

class Program
{
    static void Main(string[] args)
    {
        var penalties = new Penalties();

        var now = DateTime.Now;

        // due = today
        // should print 0
        Console.WriteLine(penalties.ComputeOverdueDaysPenalty(1234, new DateTime(now.Year, now.Month, now.Day)));

        // due = today plus 1
        var dueDate = now.AddDays(1);
        // should print 0 again
        Console.WriteLine(penalties.ComputeOverdueDaysPenalty(1234, dueDate));

        // due = today minus 1
        dueDate = dueDate.Subtract(new TimeSpan(48, 0, 0));
        // should print 1234
        Console.WriteLine(penalties.ComputeOverdueDaysPenalty(1234, dueDate));

        // due = today minus 2
        dueDate = dueDate.Subtract(new TimeSpan(24, 0, 0));
        // should print 2468
        Console.WriteLine(penalties.ComputeOverdueDaysPenalty(1234, dueDate));

        dueDate = DateTime.Parse("2016-10-02");
        // should print 12340, as of 10/12/2016
        Console.WriteLine(penalties.ComputeOverdueDaysPenalty(1234, dueDate));

        Console.ReadKey();
    }
}

只是一句话：

我觉得你在这种情况下使用int类型已经确定了一点奇怪，顺便说一句。

如果你的＆＃34;惩罚＆＃34;单位实际上是某种货币，在大多数用例中，推荐的数据类型是十进制。

＆＃39;希望这会有所帮助。

如何检查DateTime是否在特定范围内

1 个答案: