好的，我正在使用自己创建的汽车类。我正在尝试使用List<Automobile>。我正在尝试编写这个程序，它将使用List<Automobile>并将用户输入存储在我的Automobile类中。当我运行我的代码并尝试在我的List<Automobile>中放置多个汽车时，它只会覆盖用户输入的上一辆汽车。我知道我的代码很乱。我完全不习惯使用List<>和写/读文件。
以防万一我的谣言不太清楚。我想弄清楚为什么List<Automobile>当List<Automobile>写入多辆汽车时我的using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
namespace Exercise6_DealerVehicleInventory
{
class Program
{
static void Main(string[] args)
{
#region Variables/Constructors
var answer = "";
Automobile car = new Automobile();
List<Automobile> vehicle = new List<Automobile>();
#endregion
#region User Car Input
/* I might be able to put all of this in one big while loop that way I
* can have more than one vehicle wrote to this file at a time. */
Console.Write("Do you want to add a car?\nY for yes or N for no: ");
answer = Console.ReadLine();
while (answer == "Y" || answer == "y")
{
Console.Write("\nEnter the make of the car: ");
car.Make = Console.ReadLine();
Console.Write("Enter the model of the car: ");
car.Model = Console.ReadLine();
Console.Write("Enter the color of the car: ");
car.Color = Console.ReadLine();
Console.Write("Enter the year of the car: ");
car.Year = Convert.ToInt32(Console.ReadLine());
Console.Write("Enter the mileage of the car: ");
car.Mileage = Convert.ToInt32(Console.ReadLine());
vehicle.Add(car);
Console.Write("Do you want to add a car?\nY for yes or N for no: ");
answer = Console.ReadLine();
}
#endregion
#region Delete From In Memory
Console.Write("\nDo you want to delete a car?\nY for yes or N for no: ");
answer = Console.ReadLine();
if (answer == "Y" || answer == "y")
{
int i = 0;
int delEntry = 0;
foreach(Automobile automobile in vehicle)
{
Console.Write("#" + i + " = " + automobile.Make + " " + automobile.Model + " " + automobile.Color + " " + automobile.Year + " " + automobile.Mileage + "\n");
i++;
}
Console.WriteLine("\nWhat item number would you like to delete: ");
delEntry = Convert.ToInt32(Console.ReadLine());
vehicle.RemoveAt(delEntry);
}
#endregion
#region Write Data To File
Console.Write("\nDo you want to write this to a text file?\nY for yes or N for no: ");
answer = Console.ReadLine();
string mydocpath =
Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
if (answer == "Y" || answer == "y") //(string.Equals("y", answer, StringComparison.CurrentCultureIgnoreCase))
{
using (StreamWriter sw = new StreamWriter(mydocpath + @"\Vehicle.txt"))
{
foreach (Automobile automobile in vehicle)
{
sw.WriteLine(automobile.Make + " " + automobile.Model + " " + automobile.Color + " " + automobile.Year + " " + automobile.Mileage);
}
}
}
else
{
Console.WriteLine("No data wrote to file: ");
}
#endregion
#region Update Vehicle File
Console.Write("\nWould you like to add another vehicle?\nY for yes or N for no: ");
answer = Console.ReadLine();
if (answer == "Y" || answer == "y")
{
StreamReader sr = new StreamReader(mydocpath + @"\Vehicle.txt");
String line = sr.ReadLine();
Console.Write("\n" + line);
while (answer == "Y" || answer == "y")
{
Console.Write("Enter the make of the car: ");
car.Make = Console.ReadLine();
Console.Write("Enter the model of the car: ");
car.Model = Console.ReadLine();
Console.Write("Enter the color of the car: ");
car.Color = Console.ReadLine();
Console.Write("Enter the year of the car: ");
car.Year = Convert.ToInt32(Console.ReadLine());
Console.Write("Enter the mileage of the car: ");
car.Mileage = Convert.ToInt32(Console.ReadLine());
vehicle.Add(car);
Console.Write("\nDo you want to delete a car?\nY for yes or N for no: ");
answer = Console.ReadLine();
if (answer == "Y" || answer == "y")
{
int i = 0;
int delEntry = 0;
foreach (Automobile automobile in vehicle)
{
Console.Write("#" + i + " = " + automobile.Make + " " + automobile.Model + " " + automobile.Color + " " + automobile.Year + " " + automobile.Mileage + "\n");
i++;
}
Console.WriteLine("\nWhat item number would you like to delete: ");
delEntry = Convert.ToInt32(Console.ReadLine());
vehicle.RemoveAt(delEntry);
}
Console.Write("\nDo you want to write this to a text file?\nY for yes or N for no: ");
answer = Console.ReadLine();
if (answer == "Y" || answer == "y") //(string.Equals("y", answer, StringComparison.CurrentCultureIgnoreCase))
{
using (StreamWriter sw = new StreamWriter(mydocpath + @"\Vehicle.txt", true))
{
foreach (Automobile automobile in vehicle)
{
sw.WriteLine(automobile.Make + " " + automobile.Model + " " + automobile.Color + " " + automobile.Year + " " + automobile.Mileage);
}
}
}
}
}
else
{
Console.WriteLine("Nothing else was added to the file.");
}
#endregion
Console.ReadLine();
}
}
}
一直在写。
提前感谢任何人和所有人帮我解决这个问题。
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Exercise6_DealerVehicleInventory
{
class Automobile
{
private string _make;
public string Make
{
get { return _make; }
set { _make = value; }
}
private string _model;
public string Model
{
get { return _model; }
set { _model = value; }
}
private string _color;
public string Color
{
get { return _color; }
set { _color = value; }
}
private int _year;
public int Year
{
get { return _year; }
set { _year = value; }
}
private int _mileage;
public int Mileage
{
get { return _mileage; }
set { _mileage = value; }
}
}
}
以下是我的汽车课程。
scanf答案 0 :(得分：1)
可能看起来列表中的Automobile对象被覆盖，但您实际上不止一次添加相同的对象，只是覆盖了它的属性每一次。
您需要在while循环中插入此行Automobile car = new Automobile();，以便创建前一个Automobile对象的新对象独立。
while (answer == "Y" || answer == "y")
{
Automobile car = new Automobile();
...
...
...
答案 1 :(得分：1)
每次迭代while循环时都需要实例化一个新的Automobile，否则你只是在同一个实例上运行并覆盖它。
移动此行：
Automobile car = new Automobile();
到这里：
while (answer == "Y" || answer == "y")
{
Automobile car = new Automobile(); // create a new Automobile each time
Console.Write("\nEnter the make of the car: ");
car.Make = Console.ReadLine();