C#增加天数[重复]

Question

我已经完成了一个名为 nextDay 的方法，它应该增加用户在控制台中输入日期的日期。该方法还根据输入的内容更改年份并更改月份。例如。如果我在 2012 年 13 月 10 日在控制台中输入，我希望输出为 2012 年 10 月 14 日，并且我希望根据月份和年份进行。有什么方法可以实现这个或修复我当前的方法以使这个输出起作用？目前我的程序运行良好，只检索用户输入的日期并进行错误检查。我特别要求的是在用户输入内容之前获得第二天。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace date
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("\t\t\t\t\t\tNextDate Application\n\t\t\t\t\t-------------------------------------"); // title

            Console.WriteLine("This application will allow you to enter a valid date and this will get the next day.\n"); // intro of what the application does

            Console.WriteLine("please enter date as dd/MM/yyyy\n"); // tells user to input a date in the formats
            int day; // sets variable
            int month; // sets variable
            int year; // sets variable

            string[] read = Console.ReadLine().Split('/');  // "/" can be read from each value and sets new array
            day = int.Parse(read[0]); // day is first position in array
            month = int.Parse(read[1]); // month is second position in array
            year = int.Parse(read[2]); // year is third position in array

            try
            {
                Date date = new Date(day, month, year); // initialises a new date class
                Console.WriteLine("{0}/{1}/{2}", date.Day, date.Month, date.Year); // given to user as "day/month/year"
                Console.ReadLine(); // reads the line
            }
            catch (ArgumentOutOfRangeException exc)
            {
                Console.WriteLine(exc.Message); // states the message for ArgumentOutOfRangeException
                Console.Read(); // breaks
            }     
        }
        class Date
        {
            private int _month; // 1-12
            private int _day; // 1-31 depending on month
            private int _year; // sets the year

            public Date(int day, int month, int year)
            {
                Month = month;
                Day = day;         
                Year = year;
            }

            public void nextDay()
            {
                try
                {
                    _day = _day++;
                }
                catch (ArgumentOutOfRangeException)
                {
                    if (_month == 12) // e.g if month dec 31st then it does a try 
                    {
                        _month = 1; // month then = 1
                        _year++; // year increments
                    }

                    else
                    {
                        _month++; 
                    }
                    _day = 1;
                }

            }

            public int Year
            {
                get { return _year; }
                set
                {
                    if (value >= 1820 && value <= 2020) // if value is higher than or equal to 1820 and less than or equal to 2020
                        _year = value; // sets year as value
                    else
                        throw new ArgumentOutOfRangeException("Year must be between 1820 and 2020"); // throws an exception
                }
            }

            public int Month
            {
                get { return _month; }
                set
                {
                    if (value > 0 && value <= 12) // if value is higher than 0 and less than or equal to 12
                        _month = value; // sets month as value
                    else 
                        throw new ArgumentOutOfRangeException("Month must be between 1-12"); // throws an exception
                }
            }

            public int Day
            {
                get { return _day; }
                set
                {
                    int[] days = { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; // array of days of max each month

                    if (value > 0 && value <= days[_month]) // if value is higher than 0 and less than or equal to days of month
                        _day = value; // sets day as value

                    else if (_month == 2 && value == 29 && // else if month is equal to 2 and value is equal to 29
                        _year % 400 == 0 || (_year % 4 == 0 && _year % 100 != 0)) 
                        _day = value;
                    else
                        throw new ArgumentOutOfRangeException("Day is out of range"); // throws an exception
                }
            }
        }
    }
}

Answer 1

务实的答案：

public Date AddDay()
{
    var tomorrow = new DateTime(this._year, this._month, this._year).AddDays(1).Date;
    return new Date(tomorrow.Day, tomorrow.Month, tomorrow.Year);
}

或者如果你更喜欢突变

public void AddDay()
{
    var tomorrow = new DateTime(this._year, this._month, this._day).AddDays(1).Date;
    this._day = tomorrow.Day;
   //etc...
}

Answer 2

试试这个：

    private static void Main(string[] args)
    {
        DateTime theDateTime = DateTime.Now;
        DateTime tomorrow = NextDay(theDateTime);
        Console.WriteLine($"Now: {theDateTime:yy/MM/dd}\t\tTomorrow:" +
            $"{tomorrow:yy/MM/dd}");
    }

    private static DateTime NextDay(DateTime source)
    {
        return source + new TimeSpan(1, 0, 0, 0);
    }

根据需要调整您的代码。将输入解析为日期时间。使用方法。相应地解析输出。

Answer 3

您的问题是您的所有逻辑都在您的属性中，但是在您的 nextDay 方法中，您正在递增本地字段。最重要的是，以下内容不会导致任何变化。

_day = _day++;

因为这相当于

int temp = _day;
_day = _day + 1;
_day = temp;