c# - 需要类(class)帮助吗？可能很简单

Question

我想做的是让 UserID 根据类的类型生成随机值，userID 应该从 person.cs 生成。 例如，学生类生成一个学生 ID 和一个随机数，员工类应该生成一个员工 ID 和一个随机数，我遇到的问题是让任何用户 ID 样本数据显示在控制台输出中，我没有获得任何显示用户 ID 的数据，任何人都可以帮助我。

这是查看代码所需的链接

Person.cs

PersonTest.cs

Student.cs

Staff.cs

Faculty.cs

Person.cs

public class Person
{
    static string title;
    protected string firstName;
    protected string lastName;
    protected string address;
    protected string gender;
    protected string dateOfBirth;
    protected string userID;
    protected Random rnd = new Random();
    // constructors
    public Person()
    {

    }//end default constructor

    public Person(string aTitle, string aFirstName, string aLastName, string aAddress,
        string aGender, string aDateOfBirth)
    {
        title = aTitle;
        firstName = aFirstName;
        lastName = aLastName;
        address = aAddress;
        gender = aGender;
        dateOfBirth = aDateOfBirth;
        Console.WriteLine( this.DisplayInfo() );

        //create userID


        Console.WriteLine(userID);

        this.DisplayInfo();
    }//end 6-parameter constructor

刚刚添加

public string DisplayInfo()
    {
        return " You have created the person " + firstName + lastName +"\n whose address is" + address + "\n" + " whos is a " + gender + " and was born on " + dateOfBirth;
    }//end method DisplayInfo

Staff.cs Student.cs 目前具有相同的数据

  public class Staff : Person
    {
        public Staff(string aTitle, string aFirstName, string aLastName, string aAddress,
           string aGender, string aDateOfBirth)
            : base(aTitle, aFirstName, aLastName, aAddress,
                    aGender, aDateOfBirth)
        {

           this.userID = firstName.Substring(0, 1) + lastName.Substring(0, 5);

           this.userID = this.userID + this.rnd.Next(1000, 9999);


        }

PersonTest.cs

  public class PersonTest
    {
       static void Main(string[] args) 
      { 
            Person testPerson = new Student("Mr.", "Merry ", "Lanes", " 493 Bluebane RD", "Male", " 8-06-1953 ");


            Person studentPerson = new Person("Mr.", "Jerry ", "Panes", " 493 Bluebane RD", "Male", " 8-06-1953 "); 

            // THIS DATA SHOWS UP BUT NOT THE USERID



            Console.ReadLine();
        }//end main

Answer 1

您的用户 ID 为空。

在 Staff 类可以给 UserID 赋值之前，基类会尝试打印用户 ID

您的问题位于您编写“Create userID”的 person 类

如果您不熟悉继承过程，那么您就错过了关键步骤:

1:如果从子类调用父类构造函数，则所有父类都会在子类之前运行。

正如您所看到的，userID 将为空，如果您将 "create userID" 替换为 userID = "1000"; 您应该会显示一些内容。

在我看来，你只需要改变你的算法，希望是一个简单的改变。