计算将来的工作日以发送提醒电子邮件

Question

I am working on this employee performance review application. I need to send out reminder emails when the user has left 3 and 1 business days before the end of the 15 business day period.

Here is how I plan on doing it: I have the Last Modified Date for each Review which I should be able to use to find out 15 business days in future(call it deadLineToSubmit for our example). Once I got deadLineToSubmit I should check to see if currentDate + 3 days(date) == deadLineToSubmit Then add that review to my list which I will be using to send email.

I have a function called GetByDayPrior where I am sending values 3 and 1 to check if user have left 3 business days or 1. Below is the code:

    public List<int> GetByDaysPrior(int daysPrior)
    {
        List<int> response = new List<int>();

        using (DAL.HumanResourcesEntities context = new DAL.HumanResourcesEntities())
        {
            DateTime currentDate = DateTime.Now.Date;
            var lastModifiedDate = context.Reviews
                                    .Where(s => s.IsActive == false)
                                    .Where(s => s.ReviewStatusId == (int)ReviewStatuses.EmployeeSignature)
                                    .Select(v => v.ModifiedDate)
                                    .ToList();
            AddBusinessDays(lastModifiedDate, daysPrior);

            var lastRuntime = context.ApplicationRuntimeVariables.Where(y => y.ParameterName == "RemindersSentDT").Select(x => x.ParameterValue).FirstOrDefault().Date;

            DateTime deadLineToSubmitReview = currentDate.AddDays(daysPrior).Date;
            if (lastRuntime.AddHours(24).Date <= currentDate) //should it be == current date ?
            {
                var reviewIDs = context.Reviews
                                        .Where(s => s.ModifiedDate < deadLineToSubmitReview)
                                        .Where(s => s.ReviewStatusId == (int)ReviewStatuses.EmployeeSignature) //Check to make sure reminders only go when Review Status is Employee Signature
                                        .Where(s => s.IsActive == false)
                                        .Select(v => v.ReviewId)
                                        .ToList();

                response = reviewIDs.ToList();
            }

            return response;
        }
    }

I have another function called AddBusinessDays should give me the deadLineToSubmit when I pass in LastModifiedDate and 15 days as parameter. But currently its not working because firstly I cannot find out how to pass List of DataTime as a paramater in this function. Also when I defined date parameter in AddBusinessDays as List now all the instances of date and DayOfWeek are complanining

"Error 32 Cannot implicitly convert type 'System.Collections.Generic.List' to 'System.DateTime'

Below is my AddBusinessDays function.

 public static DateTime AddBusinessDays(List<DateTime> date, int days)
    {
        if (days < 0)
        {
            throw new ArgumentException("days cannot be negative", "days");
        }

        if (days == 0) return date;

        if (date.DayOfWeek == DayOfWeek.Saturday)
        {
            date = date.AddDays(2);
            days -= 1;
        }
        else if (date.DayOfWeek == DayOfWeek.Sunday)
        {
            date = date.AddDays(1);
            days -= 1;
        }

        date = date.AddDays(days / 5 * 7);
        int extraDays = days % 5;

        if ((int)date.DayOfWeek + extraDays > 5)
        {
            extraDays += 2;
        }

        return date.AddDays(extraDays);

    }

Here's what I need to know: How to send DateTime List as parameter in AddBusinessDays function. How to make AddBusinessDays function work because now we are passing list instead of single dateTime. Is my thinking logic correct to solve this issue ?

Thanks a Lot! :)

Answer 1

date is a list and not a single date.
You can make an operation on all items of the list by using Select
for example:

lastModifiedDate = AddBusinessDays(lastModifiedDate, daysPrior);

Step 1: Convert your function to receive a single date

private static DateTime AddBusinessDays(DateTime date, int days)
{
    if (days < 0)
    {
        throw new ArgumentException("days cannot be negative", "days");
    }

    if (days == 0) return date;

    if (date.DayOfWeek == DayOfWeek.Saturday)
    {
        date = date.AddDays(2);
        days -= 1;
    }
    else if (date.DayOfWeek == DayOfWeek.Sunday)
    {
        date = date.AddDays(1);
        days -= 1;
    }

    date = date.AddDays(days / 5 * 7);
    int extraDays = days % 5;

    if ((int)date.DayOfWeek + extraDays > 5)
    {
        extraDays += 2;
    }

    return date.AddDays(extraDays);
}

Step 2: Use the single date function for the list of dates

public static List<DateTime> AddBusinessDays(List<DateTime> date, int days)
{
    return date.Select(d => AddBusinessDays(d, days)).ToList();
}