c# - 难以将字符串解析为 DateTime

Question

下面的代码给出了以下错误:

"Unhandled Exception: string was not recognized as a valid DateTime.

有一个从索引 0 开始的未知单词。"

如何在这里正确地将字符串转换为 DateTime？

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

namespace Exercise
{
    class Program
    {
        static void Main(string[] args)
        {  
            Console.Write("Enter your birthday in format(dd.mm.yyyy): ");
            DateTime userBirthday = DateTime.Parse(Console.ReadLine());
            long result = DateTime.Today.Subtract(userBirthday).Ticks;
            Console.WriteLine("You are {0} years old.", new DateTime(result).Year - 1);
            Console.WriteLine("After 10 years you will be {0} years old.", new DateTime(result).AddYears(10).Year - 1);
        }
    }
}

Answer 1

您可以使用 ParseExact指定日期格式:

DateTime userBirthday  = DateTime.ParseExact(Console.ReadLine(), "dd.MM.yyyy", CultureInfo.InvariantCulture) ; 

或TryParseExact如果您不信任用户输入:

 DateTime userBirthday ; 

 if (!DateTime.TryParseExact(Console.ReadLine(), "dd.MM.yyyy", CultureInfo.InvariantCulture, DateTimeStyles.None, out userBirthday)) 
 {
   Console.WriteLine("You cheated") ; 
   return ; 
 }

可以找到可用的日期时间格式 here .