Question

我已经看过并寻找答案，但我找不到答案。是的，这是我的一类，但我的老师也不知道答案。他总是问我们是否先检查了谷歌。他正在和我们一起工作。所以，请帮助我们弄清楚什么是错的。我不断得到错误：

Field＆＃39; Program.birthday＆＃39;永远不会被赋予，并且将永远具有其Mod3_Self .....默认值为null。

同样适用于Program.Validate。

错误代码：CS0649

using System;

namespace Mod3_Self_Assessment
{
    class Program
    {
        public static dynamic firstName;
        public static dynamic lastName;
        private static dynamic birthday;
        public static dynamic tfName;
        public static dynamic tlName;
        public static dynamic course;
        public static dynamic program;
        public static dynamic degree;
        private static dynamic validate;
        public static dynamic validatebday;

        static void Main(string[] args)
        {
            GetUserInformation();
            PrintStudentDetails(firstName, lastName, birthday);
            GetSchoolInformation();
            PrintSchoolInformation(tfName, tlName, course, program, degree);
        }

        static void GetUserInformation()
        {
            Console.WriteLine("Enter the student's first name: ");
            firstName = Console.ReadLine();
            Console.WriteLine("Enter the student's last name");
            lastName = Console.ReadLine();
            //Code to finish getting the rest of the student data
            Console.WriteLine("Enter your bithdate");
            DateTime birthday = validate(Console.ReadLine());
        }

        private static DateTime Validatebday(string date)
        {
            try
            {
                DateTime birthday = DateTime.Parse(date);

                if (birthday.AddYears(18).CompareTo(DateTime.Today) >0)
                {
                    Console.WriteLine("The student is younger than 18 years of age.");
                }
                return birthday;
            }
            catch (FormatException)
            {
                Console.WriteLine("Invalid date format.");
                return DateTime.Today;
            }
        }

        static void PrintStudentDetails(string firstName, string lastName, string birthday)
        {
            Console.WriteLine("{0} {1} was born on: {2}", firstName, lastName, birthday);
            Console.ReadLine();
        }

        static void GetSchoolInformation()
        {
            Console.WriteLine("Enter the teachers first name: ");
            tfName = Console.ReadLine();
            Console.WriteLine("Enter the teachers last name: ");
            tlName = Console.ReadLine();
            Console.WriteLine("Enter the course name: ");
            course = Console.ReadLine();
            Console.WriteLine("Enter the program name: ");
            program = Console.ReadLine();
            Console.WriteLine("Enter the degree name: ");
            degree = Console.ReadLine();
        }

        static void PrintSchoolInformation(string tfName, string tlName, string course, string program, DateTime degree)
        {
           Console.WriteLine(
             "Teacher: {1}, {0} " +
             "\n Course: {2} " +
             "\n Program: {3} " +
             "\n Degree: {4}"
             , tlName, tfName, course, program, degree);
        }
    }
}

Answer 1

此代码中有两个“生日”变量。第一个被声明为类的公共静态动态属性。在方法GetUserInformation中，您声明一个名为“birthday”的局部变量，并且您正在分配“validate（Console.ReadLine（））;”到这个局部变量。您永远不会为类的属性赋值。在“GetUserInformation”中删除第二个生日变量的声明。它应该看起来像：

Console.WriteLine("Enter your bithdate");
birthday = validate(Console.ReadLine());

很确定这会解决问题。

Visual Studio C＃错误CS0649验证错误？

1 个答案: