迭代列表中的所有元素
本文关键字：元素 列表 迭代 | 更新日期: 2023-09-27 17:59:53
在过去的两周里，我一直在做一项任务，我正在努力克服这个问题。
下面是代码。这绝不是一个完整的代码，不管怎样，一旦我把所有的部分都工作好了，我就会把它整理好。在Main中，情况1：在问了一系列问题后，我想将S1传递给R1.addStudent方法，这是有效的，但是，如果你查看注册类，addStudent方法会添加S1对象/数据成员并标记到列表中。
我的问题是，一旦我尝试迭代这个列表（请参阅Module类），它就会迭代元素的数量，但会两次返回最后一个条目名称（使用toString（）方法），返回student。Name（从Person类继承的数据成员）。
我想让它迭代添加到列表中的实际名称，我该如何实现这一点？
请原谅冗长的解释，不要因为代码不整洁而大发雷霆，我会解决的。
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace P3_O_O_P
{
public class Module
{
private string moduleName;
private double moduleCode;
public List<Registration> registerList = new List<Registration>();
public Module(string newModuleName, double newModuleCode)
{
moduleName = newModuleName;
moduleCode = newModuleCode;
}
public Module()
{
}
public void Enrol(Student student, int mark, Classroom objClassroom)
{
Console.Clear();
Console.Write("'nBelow are a list of modules that are currently available: 'n");
Console.Write("'n1) Software Development'n");
Console.Write("'n2) Chemistry'n");
Console.Write("'n3) Science'n");
Console.Write("'n4) Biology'n");
Console.Write("'nSelection: ");
int choice = Convert.ToInt32(Console.ReadLine());
switch (choice)
{
case 1:
objClassroom.addStudentProgramming(student, mark);
break;
case 2:
objClassroom.addStudentChemistry(student, mark);
break;
case 3:
objClassroom.addStudentScience(student, mark);
break;
case 4:
objClassroom.addStudentBiology(student, mark);
break;
}
}
public void studentListMarks()
{
for (int i = 0; i < registerList.Count; i++)
{
Console.WriteLine("'nStudent name: " + registerList[i].ToString() + "'nCurent student marks" + registerList[i].Mark);
}
}
public string ModuleName
{
get
{
return moduleName;
}
set
{
moduleName = value;
}
}
public double ModuleID
{
get
{
return moduleCode;
}
set
{
moduleCode = value;
}
}
public void RemoveStudent()
{
throw new System.NotImplementedException();
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace P3_O_O_P
{
public class Registration
{
Student student; //Links student to registration, forcing data-integrity and granting a link to its data-members.
private int mark;
public Registration(Student ST, int mark) //passes the student object to the constructor.
{
this.mark = mark;
student = ST; //Initializes the student object. allocates memory.
}
public int Mark
{
get
{
return mark;
}
set
{
mark = value;
}
}
public int updateMark()
{
Console.Write("Please enter a new mark: ");
mark = Convert.ToInt16(Console.ReadLine());
return mark;
}
public void viewStudentMark()
{
Console.Write("'nStudent mark = : " + Mark);
}
public void addStudent(Student S1, Module objMod, Classroom objClassroom, int mark)
{
objMod.registerList.Add(new Registration(S1, mark));
objMod.Enrol(S1, Mark, objClassroom);
}
public string studentSubject()
{
return student.Subject;
}
public string ToString(Student S1)
{
return student.Name;
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace P3_O_O_P
{
class Execute
{
static void Main(string[] args)
{
bool repeatMenu = true;
int choice = 0;
int mark = 0;
Student S1 = new Student();
Registration R1 = new Registration(S1, mark);
Module M1 = new Module();
Classroom C1 = new Classroom();
do
{
Console.ForegroundColor = ConsoleColor.Red;
Console.BackgroundColor = ConsoleColor.White;
Console.WriteLine("'n1) Enrol a student");
Console.WriteLine("'n2) View students in Programming");
Console.WriteLine("'n3) View students in Chemistry");
Console.WriteLine("'n4) View students in Science");
Console.WriteLine("'n5) View students in Biology");
Console.WriteLine("'n6) View Classrooms (Modules)");
Console.WriteLine("'n7) View all Students");
Console.WriteLine("'n8) Update student mark ");
Console.WriteLine("'n9) View student mark");
Console.WriteLine("'n10) Exit Application");
Console.Write("'nSelection: ");
choice = Convert.ToInt32(Console.ReadLine());
repeatMenu = false;
Console.Clear();
switch (choice)
{
case 1:
Console.Write("'nPlease begin by entering your name: ");
S1.Name = Console.ReadLine();
Console.Write("'nPlease enter your Date of Birth: ");
S1.StudentDOB = Convert.ToDouble(Console.ReadLine());
Console.Write("'nPlease enter your preferred subject: ");
S1.Subject = Console.ReadLine();
Console.Write("'nPlease hand the console to the administrator, thank you.'n");
Console.Write("'nPlease enter/allocate an I.D.: ");
S1.ID = Convert.ToDouble(Console.ReadLine());
Console.Write("'nPlease enter a mark: ");
mark = Convert.ToInt32(Console.ReadLine());
R1.addStudent(S1, M1, C1, mark);
repeatMenu = true;
break;
case 2:
C1.ViewStudentsProgramming();
repeatMenu = true;
break;
case 3:
C1.viewStudentsChemistry();
repeatMenu = true;
break;
case 4:
C1.viewStudentsScience();
repeatMenu = true;
break;
case 5:
C1.viewStudentsBiology();
repeatMenu = true;
break;
case 6:
Console.Write("'nAvailable classrooms: 'n");
Console.Write("'nSoftware Development'n");
Console.Write("'nChemistry'n");
Console.Write("'nScience'n");
Console.Write("'nBiology'n");
Console.Write("'nPress any key to continue!");
Console.ReadKey();
Console.Clear();
repeatMenu = true;
break;
case 7:
M1.studentListMarks();
repeatMenu = true;
break;
case 8:
R1.updateMark();
repeatMenu = true;
break;
case 9:
R1.viewStudentMark();
repeatMenu = true;
break;
default:
Console.WriteLine("'nThank you for using this application, goodbye!'n");
break;
}
} while (repeatMenu == true);
}
}
}
正如评论中所指出的，您的问题很可能与列表中有两次相同的条目有关。但我鼓励您对列表本身进行迭代，而不是将其视为数组。
代替：
for (int i = 0; i < registerList.Count; i++)
{
Console.WriteLine("'nStudent name: " + registerList[i].ToString() + "'nCurent student marks" + registerList[i].Mark);
}
只需这样做：
foreach(var student in registerList)
{
Console.WriteLine("'nStudent name: " + student.ToString() + "'nCurent student marks" + student.Mark);
}
据我所见，Student只有一个实例，因此Registration的每个实例都指向同一个Student。