我正在尝试使用对象列表创建一个简单的模拟,并使其重复执行计算来代表农民。它有一种方法可以按随机百分比增加农民拥有的资金量,每个农民的起始金额为 100 美元
public class Farmer
{
public decimal money { get; set; }
public Farmer()
{
money = 100;
}
public void doOneYear() //Represents how much money the farmer earned
{
Random random = new Random();
decimal growth = random.Next(0, 100);
decimal percentage = (growth / 1000);
money = money * (1 + percentage);
}
}
运行的代码是这样的
List<Farmer> farmers = new List<Farmer>();
int count = 0;
while (count < 10)
{
Farmer newFarmer = new Farmer();
farmers.Add(newFarmer);
count++;
}
foreach(var farmer in farmers)
{
int years = 0;
while (years < 10)
{
farmer.doOneYear();
years++;
}
}
foreach (var farmer in farmers)
{
MessageBox.Show(farmer.money.ToString());
}
但是我得到的结果只是列表中重复的第一个对象。如果我在调试模式下逐步完成整个过程,它工作正常,但当我让它运行时,对象似乎是重复的。
来自 MSDN:“默认种子值源自系统时钟,并且具有有限的分辨率。因此,通过调用默认构造函数连续创建的不同 Random 对象将具有相同的默认种子值,因此,将产生相同的随机数集。”
我个人只是将 Random 实例设为静态成员:
public class Farmer
{
public decimal money { get; set; }
private static Random random = new Random();
public Farmer()
{
money = 100;
}
public void doOneYear() //Represents how much money the farmer earned
{
decimal growth = random.Next(0, 100);
decimal percentage = (growth / 1000);
money = money * (1 + percentage);
}
}
由于程序运行速度如此之快,并且我相信 Random 类使用时间设置作为其默认种子,因此您需要自己将种子注入到 Random 调用中。 (这也可能是为什么您在调试时会看到不同的数字 - 您使程序运行得更慢,因此 Random 类会输出不同的数字)。
我这样做了,并在输出中看到每个农民的数字不同。不过,您可能想使用不同的种子生成。
public class Farmer
{
private static int seed = 17;
public decimal money { get; set; }
public int FarmerID { get; set; }
public Farmer(int id)
{
money = 100;
FarmerID = id;
}
public void doOneYear() //Represents how much money the farmer earned
{
seed++;
Random random = new Random(seed);
decimal growth = random.Next(0, 100);
decimal percentage = (growth / 1000);
money = money * (1 + percentage);
}
}
public class MyRandom
{
public static Random _random = new Random();
public Random Random
{
get
{
if (_random == null)
_random = new Random();
return _random;
}
}
}
public class Farmer
{
public decimal money { get; set; }
public Farmer()
{
money = 100;
}
public void doOneYear() //Represents how much money the farmer earned
{
MyRandom random = new MyRandom();
decimal growth = random.Random.Next(0, 100);
decimal percentage = (growth / 1000);
money = money * (1 + percentage);
}
}
您可以为 Random 实现一个自定义类,并对 Random 对象使用单例方法,这样您就可以使用新的 MyRandom 并获得所需的结果,而无需修改您的 Farmer 类。
List<Farmer> farmers = new List<Farmer>();
int count = 0;
while (count < 10)
{
Farmer newFarmer = new Farmer();
farmers.Add(newFarmer);
count++;
}
foreach (var farmer in farmers)
{
int years = 0;
while (years < 10)
{
farmer.doOneYear();
years++;
}
}
foreach (var farmer in farmers)
{
Console.WriteLine(farmer.money.ToString());
}
结果:
(我使用LinqPad进行测试)
希望有帮助