Question

我想在ArrayList中创建一个Student class，但无法添加student1, student2, student3来自Main的值public class Program { static void Main(string[] args) { Student student1 = new Student("John", "Grodinskiy", "12/07/1996", "Lesy Ukrainky 88", "Cherkasy", "58000", "Ukraine"); Student student2 = new Student("Niko", "Rekun", "03/02/1995", "Promyslova 86", "Velykiy Bychkiv", "90615","Ukraine"); Student student3 = new Student("Veronica","Kran", "26/03/1991", "Uzhgorodska 1", "Svalyava", "59432", "Ukraine"); ........ Console.WriteLine("The {0} program contains the {1} of Sciense degree\nThe {2} of Sciense degree contains the course {3}\n{4} course contains {5} students", program.Program_name1, myDegree.degree_name, myDegree.degree_name, myCourse.Course_name, myCourse.Course_name, Student.Counter); student1.TakeTest(); student2.TakeTest(); student3.TakeTest(); } }。如何在不将其替换为其他课程的情况下使student1 / 2/3可见？这是我的代码的一部分：

    public class Student:Person
    {
        public Student(string name, string last_name, string birthday, string address, string city, string zip, string country)
        {
            this.Name = name;
            this.Last_name = last_name;
            this.Birth_date = birthday;
            this.Address = address;
            this.City = city;
            this.Zip = zip;
            this.Country = country;
            Counter++
        }

        public void TakeTest()
        {
            Take_counter++;
            Console.WriteLine("{0} student took the test.",Take_counter);
        }

        public void add_student()
        {
             ArrayList students = new ArrayList();
             students.Add(student1);
        }
    }

// Class

//PROPERTIES

    /// <summary>
    /// Property for "Title"
    /// Read & Write property for attribute "Title"
    /// set method currently has no protection
    /// </summary>
    ///
    public string Title
    {
        get { return title; }
        set { title = value; }
    }

    public string FirstName
    {
        get { return firstname; }
        set { firstname = value; }
    }

    public string MiddleName
    {
        get { return middlename; }
        set { middlename = value; }
    }

    public string LastName
    {
        get { return lastname; }
        set { lastname = value; }
    }

Answer 1

代码的以下部分不属于Student类。

public void add_student()
{
     ArrayList students = new ArrayList();
     students.Add(student1);
}

因为学生不是学生的集合，也不包含学生集合。

您可以做的一件事是创建一个代表学生集合的新课程，让我们称之为StudentProgram：

public class StudentProgram
{
    private readonly List<Student> _students = new List<Student>();

    public StudentProgram(string programName)
    {
        Name = programName;
    }

    public readonly string Name;

    public void AddStudent(Student newStudent)
    {
        _students.Add(newStudent);
    }

    public IEnumerable<Student> AllStudents
    {
        get { return _students; }
    }
    public int NumberOfStudents
    {
        get { return _students.Count; }
    }
}

然后，您可以在Main中使用此功能：

static void Main(string[] args)
{ 
    var scienceProgram = new StudentProgram("science");

    scienceProgram.Add(new Student(
        "John", "Grodinskiy", "12/07/1996", 
        "Lesy Ukrainky 88", "Cherkasy", "58000", "Ukraine"));
    scienceProgram.Add(new Student(
        "Niko", "Rekun", "03/02/1995", 
        "Promyslova 86", "Velykiy Bychkiv", "90615","Ukraine"));
    scienceProgram.Add(new Student(
        "Veronica","Kran", "26/03/1991", 
        "Uzhgorodska 1", "Svalyava", "59432", "Ukraine"));

    ........

    Console.WriteLine(
        "The {0} program has {1} students",
        scienceProgram.Name, scienceProgram.NumberOfStudents);

     foreach (var student in scienceProgram.AllStudents)
         student.TakeTest();
}

Answer 2

    public class Student:Person
    {
        public static List<Student> Students = new List<Student>();

        //....

        public static void add_student(Student newStudent)
        {             
             Students.Add(newStudent);
        }
    }

学生列表是静态的，这意味着你将拥有一个全班学生列表，从你认为你想要实现的构造函数和方法。

Answer 3

这是一个非常令人困惑的设计，如果你想在add_student方法中添加学生，那么你应该使用：

static void Main(string[] args)
{
    ...
    student1.Add(student1);
}

然后在你的主要方法

from tkinter import *
from functools import partial

canvas_height = 400
canvas_width = 600
canvas_colour = "grey50"
moveBoolean = "True"

def move_it(ctr=0):
    if ctr < len(coords):
        x, y = coords[ctr]
        ctr += 1
        print ctr, x, y
        canvas.move(square, x, y)
        window.after(1000, partial(move_it, ctr))

window = Tk()

canvas = Canvas(bg=canvas_colour, height=canvas_height,
         width=canvas_width, highlightthickness=0)
canvas.pack()

square = canvas.create_rectangle(50, 50, 50, 50, width=50, fill="black")

coords = ((90, 90),
          (180, 180),
          (50, 50))
move_it()

window.mainloop()

将学生添加到一个名为student的课程中虽然没有多大意义（因为你将学生传递给自己，你可以使用'this'关键字访问），如果你进一步解释该程序，也许我可以帮助你改善它。

Answer 4

也许以下答案太简单了。也许是因为我没有正确地解决你的问题。但如果你的问题出在这里：

public void add_student()
    {
         ArrayList students = new ArrayList();
         students.Add(student1);
    }

因此，如果您想将新的students存储到ArrayList students，那么您可以执行以下操作：

ArrayList students = new ArrayList();
public void add_student(student1)
    {          
         students.Add(student1);
    }

您可以通过以下方式在主要课程中添加students

Student person = new Student(...);
person.add_student("any student to be added");

如何从另一个类调用（make visible）变量？

4 个答案: