如何在C＃中打印出来自用户的输入？

嘿，我几乎没有开始我的C＃课程，所以我对编程很新。 我无法打印出用户的输入。 当我要求用户输入本周运行的里程数时，它将显示输入但是然后打印出0.当它假设打印出“这辆车归”时，我得到一个formatexception是未处理的错误并停止程序。 特别是它说Index（从零开始）必须大于或等于零且小于参数列表的大小。 我该如何解决？

using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace Homework1 { class Car { private string color; private int numOfWheels; private int startingPoint; private int mileage; private int currentSpeed; public Car() { color = ""; NumOfWheels = 4; StartingPoint = 100000; CurrentSpeed = 0; Mileage = 0; } public Car(string color, int numOfWheels, int startingPoint, int currentSpeed, int mileage) { Color = color; NumOfWheels = numOfWheels; StartingPoint = startingPoint; CurrentSpeed = currentSpeed; Mileage = mileage; } public virtual string Color { get { return color; } set { color = value; } } public virtual int NumOfWheels { get { return numOfWheels; } set { numOfWheels = value; } } public virtual int StartingPoint { get { return startingPoint; } set { startingPoint = value; } } public virtual int CurrentSpeed { get { return currentSpeed; } set { currentSpeed = value; } } public virtual int Mileage { get { return mileage; } set { mileage = value; } } public override string ToString() { return (" color " + color + " numOfWheels" + numOfWheels + "startingPoint " + startingPoint + "mileage" + mileage + "current speed" + currentSpeed); } } } ******************************************************************************** ///this is the test case using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace Homework1 { class CarTest { static void Main(string[] args) { Car myCar = new Car(); Console.WriteLine("*****************************"); Console.WriteLine("* *"); Console.WriteLine("* WELCOME TO CAR MANAGER *"); Console.WriteLine("* By <> *"); Console.WriteLine("* *"); Console.WriteLine("*****************************"); Console.WriteLine("\nEnter the number of wheels of a car"); int numOfWheels = Console.Read(); Console.WriteLine(myCar.NumOfWheels); Console.WriteLine("Enter the color of the car"); String color = Console.ReadLine(); Console.WriteLine(myCar.Color); Console.WriteLine("Current mileage will be set to zero"); Console.WriteLine("The current starting point will be set to 100000"); Console.Write("The current status of your car \n{0:D} Wheels, \n{1}, \n{2:D} Miles and \nCAR POINT = {3:D}", myCar.NumOfWheels, myCar.Color, myCar.Mileage, myCar.StartingPoint); Console.WriteLine("\nEnter the owner's name"); String name = Console.ReadLine(); Console.WriteLine("Enter the miles the car ran in this week"); int mileage = Console.Read(); Console.WriteLine(myCar.Mileage); Console.WriteLine("This car is owned by n{1}", name); ///this is where the program stops and i get the error message Console.WriteLine("===>The current status of your car:"); Console.WriteLine("Wheels: " + myCar.NumOfWheels); Console.WriteLine("Color: " + myCar.Color); Console.WriteLine("Current Mileage: " + myCar.Mileage); Console.WriteLine("Starting Point: " + myCar.StartingPoint); Console.WriteLine("************ Thank you for using CAR MANAGER *************"); Console.WriteLine("----------------------------------------------------------"); Console.WriteLine("----------------------------------------------------------"); Console.WriteLine("Press ENTER to close console……."); } } } 

Answer 1

您的所有代码都有相同的错误：

 Console.WriteLine("\nEnter the number of wheels of a car"); int numOfWheels = Console.Read(); Console.WriteLine(myCar.NumOfWheels); 

您将值存储在时间变量中，但是您没有将它分配给myCar实例，那么myCar。（无论如何）将始终为null。

将它分配给类属性，它应该工作：

 Console.WriteLine("\nEnter the number of wheels of a car"); myCar.NumOfWheels = Console.Read(); Console.WriteLine(myCar.NumOfWheels);