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c# - 试图从一个类中创建一个对象列表，但它似乎不起作用

问题描述

所以我正在尝试创建对象列表，其数量由用户输入确定。然后我通过一个循环来收集每个对象所需的数据。我尝试过使用和不使用构造函数，以及几种不同的变体，但是每当我尝试打印结果时，什么都不会打印。就好像它正在创建空对象，所以当我运行一个 foreach 循环时，它什么也不打印，然后在 ReadLine 上挂起，直到我按下一个键。

有任何想法吗？

编辑：用完整代码替换了代码摘要，主要是为了确保我实际上没有添加或忘记括号。

public class TermItem
    {
        // declare variables
        public int Id { get; set; }
        public double Area { get; set; }
        public float Gravity { get; set; }
        public float Weight { get; set; }
        public string Planet { get; set; }
        public double TerminalV { get; set; }
        public double TimeToV { get; set; }
    }

    class Program
    {

        static void Main(string[] args)
        {
            // list of code variables
            int objectCount = 0;
            char confirmation = 'n';
            string planet;
            float Cd = .1f;
            float dt = .2f;
            float gravity= 9.8f;
            float P = 1f;


            // confirmation loop for number of objects to test
            while (confirmation != 'y' && confirmation != 'Y')
            {
                Console.WriteLine("Please enter the number of spherical objects you wish to test:");
                var objectAttempt = Console.ReadLine();
                while (!int.TryParse(objectAttempt, out objectCount))
                {
                    Console.WriteLine("Please enter a valid integer.");
                    objectAttempt = Console.ReadLine();
                }
                objectCount = int.Parse(objectAttempt);
                Console.WriteLine("You entered " + objectCount + " objects. Is this correct? Y/N");
                var confirmationAttempt = Console.ReadLine();
                while (!Char.TryParse(confirmationAttempt, out confirmation))
                {
                    Console.WriteLine("Please enter Y/N");
                    confirmationAttempt = Console.ReadLine();
                }
                if (confirmation == 'y' || confirmation == 'Y')
                {
                    break;
                }
                while (confirmation != 'y' && confirmation != 'Y')
                {
                    if (confirmation == 'n' || confirmation == 'N')
                    {
                        confirmationAttempt = Console.ReadLine();
                        while (!Char.TryParse(confirmationAttempt, out confirmation))
                        {
                            Console.WriteLine("Please enter Y/N");
                            confirmationAttempt = Console.ReadLine();
                        }
                    }
                    else
                    {
                        Console.WriteLine("Please enter Y/N");
                        confirmationAttempt = Console.ReadLine();
                        while (!Char.TryParse(confirmationAttempt, out confirmation))
                        {
                            Console.WriteLine("Please enter Y/N");
                            confirmationAttempt = Console.ReadLine();
                        }
                    }
                }
            }

            List<TermItem> myItems = new List<TermItem>();

            // request the base parameters for each object
            for (int i = 0; i < objectCount; i++)
            {
                // reset 'confirmation' for confirmation loop initialization
                confirmation = 'n';

                Console.WriteLine();

                // confirmation loop for base parameters
                while (confirmation != 'y' && confirmation != 'Y')
                {
                    // request the size of the objects
                    if (i == 0)
                    {
                        Console.WriteLine("Please enter the frontal surface area of the 1st object in square meters:");
                    }
                    else if (i == 1)
                    {
                        Console.WriteLine("Please enter the frontal surface area of the 2nd object in square meters:");
                    }
                    else if (i == 2)
                    {
                        Console.WriteLine("Please enter the frontal surface area of the 3rd object in square meters:");
                    }
                    else
                    {
                        Console.WriteLine("Please enter the frontal surface area of the " + i+1 + "th object in square meters:");
                    }
                    var sizeAttempt = Console.ReadLine();
                    float size;
                    while (!float.TryParse(sizeAttempt, out size))
                    {
                        Console.WriteLine("Please enter a valid number.");
                        sizeAttempt = Console.ReadLine();
                    }
                    float area = float.Parse(sizeAttempt);


                    // request the mass of the objects to prevent confusion in giving weight due to difference in gravity on planets
                    if (i == 0)
                    {
                        Console.WriteLine("Please enter the mass of the 1st object in kilograms:");
                    }
                    else if (i == 1)
                    {
                        Console.WriteLine("Please enter the mass of the 2nd object in kilograms:");
                    }
                    else if (i == 2)
                    {
                        Console.WriteLine("Please enter the mass of the 3rd object in kilograms:");
                    }
                    else
                    {
                        Console.WriteLine("Please enter the mass of the " + i+1 + "th object in kilograms");
                    }
                    var massAttempt = Console.ReadLine();
                    float mass;
                    while (!float.TryParse(massAttempt, out mass))
                    {
                        Console.WriteLine("Please enter a valid number.");
                        massAttempt = Console.ReadLine();
                    }
                    mass = float.Parse(massAttempt);


                    // request the planet to test on
                    if (i == 0)
                    {
                        Console.WriteLine("Please select a planet from the list below for the 1st object:");
                    }
                    else if (i == 1)
                    {
                        Console.WriteLine("Please select planet from the list below for the 2nd object:");
                    }
                    else if (i == 2)
                    {
                        Console.WriteLine("Please select planet from the list below for the 3rd object:");
                    }
                    else
                    {
                        Console.WriteLine("Please select planet from the list below for the " + i+1 + "th object:");
                    }
                    string[] planetList = { "Venus", "Earth", "Mars", "Jupiter", "Saturn", "Uranus", "Neptune" };
                    for (int index = 0; index < planetList.Length; index++)
                    {
                        Console.Write(planetList[index] + "    ");
                    }
                    Console.WriteLine();
                    Console.WriteLine("Note: Planet spellings are case sensitive.");
                    planet = Console.ReadLine();
                    while (!planetList.Contains(planet))
                    {
                        Console.WriteLine("Please enter a valid planet from the list.");
                        planet = Console.ReadLine();
                    }

                    // set the planet specifc parameters for calculations
                    if (planet == "Earth")
                    {
                        gravity = 9.82f;
                        P = 1.29f;
                    }
                    else if (planet == "Mars")
                    {
                        gravity = 3.721f;
                        P = .02f;
                    }
                    else if (planet == "Venus")
                    {
                        gravity = 8.87f;
                        P = 65f;
                    }
                    else if (planet == "Jupiter")
                    {
                        gravity = 24.79f;
                        P = .16f;
                    }
                    else if (planet == "Saturn")
                    {
                        gravity = 10.44f;
                        P = .19f;
                    }
                    else if (planet == "Uranus")
                    {
                        gravity = 8.87f;
                        P = .42f;
                    }
                    else if (planet == "Neptune")
                    {
                        gravity = 11.15f;
                        P = .45f;
                    }
                    else
                    {
                        Console.WriteLine("Please enter a valid planet.");
                    }

                    Console.WriteLine();

                    // verify the base parameters for each object
                    Console.WriteLine("You entered ");
                    Console.WriteLine("Item: " + i + 1 + ", Area: " + area + " m^2, Weight: " + Math.Round((mass * gravity), 2) + ", on Planet: " + planet + ".");
                    Console.WriteLine();

                    Console.WriteLine("Are these parameters correct? Y/N");

                    var confirmationAttempt = Console.ReadLine();
                    while (!Char.TryParse(confirmationAttempt, out confirmation))
                    {
                        Console.WriteLine("Please enter Y/N");
                        confirmationAttempt = Console.ReadLine();
                    }
                    if (confirmation == 'y' || confirmation == 'Y')
                    {
                        break;
                    }
                    while (confirmation != 'y' && confirmation != 'Y')
                    {
                        if (confirmation == 'n' || confirmation == 'N')
                        {
                            confirmationAttempt = Console.ReadLine();
                            while (!Char.TryParse(confirmationAttempt, out confirmation))
                            {
                                Console.WriteLine("Please enter Y/N");
                                confirmationAttempt = Console.ReadLine();
                            }
                        }
                        else
                        {
                            Console.WriteLine("Please enter Y/N");
                            confirmationAttempt = Console.ReadLine();
                            while (!Char.TryParse(confirmationAttempt, out confirmation))
                            {
                                Console.WriteLine("Please enter Y/N");
                                confirmationAttempt = Console.ReadLine();
                            }
                        }
                    }
                    Console.WriteLine();

                    // create object and assign values
                    myItems.Add(new TermItem
                    {
                        Id = i + 1,
                        Area = area,
                        Weight = mass*gravity,
                        Planet = planet,
                        TerminalV = (Math.Sqrt(2 * mass * gravity) / (Cd * P * area)),
                        TimeToV = (Math.Sqrt(2 * mass * gravity) / (Cd * P * area) + area * dt) * (1 - Cd * dt)
                    });
                }
            }

            // print all data
            Console.WriteLine();
            Console.WriteLine("Terminal Velocity Outputs for provided objects and environments");
            foreach (var item in myItems)
            {
                Console.WriteLine("ID: " + item.Id);
                Console.WriteLine("Area: " + item.Area + "m^2");
                Console.WriteLine("Weight: " + Math.Round(item.Weight, 2) + "kg");
                Console.WriteLine("Planet: " + item.Planet);
                Console.WriteLine("Terminal Velocity: " + Math.Round(item.TerminalV, 2) + "m/s");
                Console.WriteLine("Time to Reach Terminal: " + Math.Round(item.TimeToV, 2) + "s");
            }
            Console.Read(); // keep the console open until key press
        }
    }

标签： c#listclassobject

解决方案

要看的地方是：

Console.WriteLine("Are these parameters correct? Y/N");
}
Console.WriteLine();
// create object and assign values

要解决您的主要问题，您必须卸下支架。

Console.WriteLine("Are these parameters correct? Y/N");

Console.WriteLine();
// create object and assign values

如果您询问“这些参数是否正确？是/否”，您还应该等待输入并处理它。埃里克

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