C#控制台员工管理程序List无法保存用户输入数据问题

你的员工数据无法留存的核心问题是变量作用域生命周期错误，附带还有3个影响功能使用的小问题：

• 核心bug：List<Employee> EmployeesList = new List<Employee>(); 被写在了while (keepRunning)循环的内部。C#中定义在大括号{}代码块内的局部变量，仅在当前次代码块执行时有效，每轮循环结束后，上一轮创建的列表就会被系统回收，下一轮循环启动时会重新创建一个全新的空列表，之前存入的员工数据自然全部丢失。
• 功能入口缺失：你写的遍历打印全量员工的逻辑绑定在case 0分支，但菜单提示里只列了1/2/3三个选项，用户完全不知道按0可以查看员工列表。
• 删除逻辑提示错误：当找不到对应员工时，employeeToBeDeleted是null值，此时输出$"Could not find {employeeToBeDeleted}"只会打印空内容，不会显示用户输入的待删除姓氏，提示无意义。
• 冗余代码：你定义了本地函数AddToList但全程没有调用，属于无效代码。

1. 把员工列表的初始化代码挪到while循环外部，放在Main方法刚进入、循环启动前的位置，保证整个程序运行期间列表只创建一次，不会被反复重置。
2. 调整菜单提示，增加“按0查看所有员工”的说明，也可以根据需求把查看员工的逻辑整合到其他分支（比如加完员工、删完员工自动打印当前列表）。
3. 修复删除失败的提示文本，直接输出用户输入的待删除姓氏即可。
4. 删掉没用到的AddToList冗余函数。

using Employees;

namespace Inheritance
{
    public class Program
    {
        static void Main(string[] args)
        {
            bool keepRunning = true;
            // 列表挪到循环外，整个程序运行周期只初始化一次
            List<Employee> EmployeesList = new List<Employee>();

            while (keepRunning)
            {
                // 菜单提示补上0选项
                Console.WriteLine("TIFFANYS & CO - PRIVATE PROGRAM TM\nPress the number of the action you want to pursue, and press [ENTER].\n0) View all Employees\n1) Add an Employee\n2) Delete an Employee\n3) Exit");
                var menuChoice = Int32.Parse(Console.ReadLine());
                switch (menuChoice)
                {
                    case 0:
                        foreach (Employee item in EmployeesList)                    
                        {                                                    
                            Console.WriteLine(item.firstName + " " + item.lastName + " " + item.salary);
                        }
                        break;
                    case 1:
                        Console.WriteLine("a) Add a Manager\nb) Add an Engineer\nc) Add a Researcher");
                        var menuChoice1 = Console.ReadLine();

                        switch (menuChoice1)
                        {
                            case "a":
                                Console.WriteLine("Please type in the first name of the manager and press [ENTER]:");
                                string managerFirstName = Console.ReadLine();
                                Console.WriteLine("Please type in the last name of the manager and press [ENTER]:");
                                string managerLastName = Console.ReadLine();
                                Console.WriteLine("Please type in the salary of the manager and press [ENTER]:");
                                int managerSalary = Int32.Parse(Console.ReadLine());
                                Console.WriteLine("Please type in how many meetings the manager will attend weekly and press [ENTER]:");
                                int managerMeetings = Int32.Parse(Console.ReadLine());
                                Console.WriteLine("Please type in how many vacation-weeks the manager has annually and press [ENTER]:");
                                int managerVacationWeeks = Int32.Parse(Console.ReadLine());

                                Manager manager = new(managerFirstName, managerLastName, managerSalary, managerMeetings, managerVacationWeeks);
                                EmployeesList.Add(manager);
                                foreach (var employee in EmployeesList)
                                {
                                    Console.WriteLine(employee);
                                }
                                break;

                            case "b":
                                Console.WriteLine("Please type in the first name of the engineer and press [ENTER]:");
                                string engineerFirstName = Console.ReadLine();
                                Console.WriteLine("Please type in the last name of the engineer and press [ENTER]:");
                                string engineerLastName = Console.ReadLine();
                                Console.WriteLine("Please type in the salary of the engineer and press [ENTER]:");
                                int engineerSalary = Int32.Parse(Console.ReadLine());
                                Console.WriteLine("How many years of experience does the engineer have? Type the number of years and press [ENTER]:");
                                int engineerExperience = Int32.Parse(Console.ReadLine());
                                Console.WriteLine("What kind of engineering is the engineers field? Please write their field and press [ENTER]:");
                                string engineerField = Console.ReadLine();

                                Engineer engineer = new(engineerFirstName, engineerLastName, engineerSalary, engineerExperience, engineerField);
                                EmployeesList.Add(engineer);
                                break;

                            case "c":
                                Console.WriteLine("Please type in the first name of the researcher and press [ENTER]:");
                                string researcherFirstName = Console.ReadLine();
                                Console.WriteLine("Please type in the last name of the researcher and press [ENTER]:");
                                string researcherLastName = Console.ReadLine();
                                Console.WriteLine("Please type in the salary of the researcher and press [ENTER]:");
                                int researcherSalary = Int32.Parse(Console.ReadLine());
                                Console.WriteLine("What university did the researcher get their Doctorate? Please type in the name of the university and press [ENTER]:");
                                string researcherUniversity = Console.ReadLine();
                                Console.WriteLine("What was the thesis statement of the researchers doctorate? Please type in the thesis question and press [ENTER]:");
                                string researcherThesis = Console.ReadLine();
                                Researcher researcher = new(researcherFirstName, researcherLastName, researcherSalary, researcherUniversity, researcherThesis);
                                EmployeesList.Add(researcher);
                                break;
                        }
                        break;

                    case 2:
                        Console.WriteLine("What is the last name of the employee to be deleted?");
                        string toDeleteLastName = Console.ReadLine();
                        Employee employeeToBeDeleted = EmployeesList.Find(e => e.lastName == toDeleteLastName);
                        if (employeeToBeDeleted != null)
                            EmployeesList.Remove(employeeToBeDeleted);
                        else
                            // 修复提示内容，直接输出用户输入的姓氏
                            Console.WriteLine($"Could not find employee with last name: {toDeleteLastName}");
                        break;

                    case 3:
                        keepRunning = false;
                        break;
                }
            }
        }
    }
}

初学者提示：写循环逻辑的时候要特别注意变量定义的位置，如果你需要在多轮循环中共享同一个变量的数据，就一定要把变量定义在循环体外面；如果每轮循环都需要全新的初始值，再把变量定义在循环内部。

内容的提问来源于stack exchange，提问作者ayoubzann