浅析C#如何随机获取枚举中的变量

using System;
​
public enum Color
{
    Red,
    Green,
    Blue,
    Yellow,
    Black
}
​
public static class EnumHelper
{
    private static Random random = new Random();
    
    public static T RandomEnumValue<T>() where T : Enum
    {
        Array values = Enum.GetValues(typeof(T));
        int index = random.Next(values.Length);
        return (T)values.GetValue(index);
    }
}
​
// 使用示例
Color randomColor = EnumHelper.RandomEnumValue<Color>();
Console.WriteLine(randomColor); // 输出可能为：Blue

using System;
using System.Linq;
​
public enum Direction
{
    North,
    South,
    East,
    West
}
​
public static class EnumRandomizer
{
    private static Random random = new Random();
    
    public static T RandomValue<T>() where T : Enum
    {
        Array values = Enum.GetValues(typeof(T));
        return (T)values.GetValue(random.Next(values.Length));
    }
    
    // 更简洁的LINQ写法
    public static T RandomValueLinq<T>() where T : Enum
    {
        return Enum.GetValues(typeof(T)).Cast<T>().ElementAt(random.Next(0, Enum.GetValues(typeof(T)).Length));
    }
}
​
// 使用示例
Direction randomDirection = EnumRandomizer.RandomValue<Direction>();
Console.WriteLine(randomDirection); // 输出可能为：South

using System;
using System.Collections.Generic;
​
public enum Size
{
    Small,
    Medium,
    Large
}
​
public static class WeightedEnumRandomizer
{
    private static Random random = new Random();
    
    public static T RandomValue<T>(params (T value, int weight)[] weightedValues) where T : Enum
    {
        int totalWeight = 0;
        foreach (var (_, weight) in weightedValues)
        {
            totalWeight += weight;
        }
        
        int randomValue = random.Next(0, totalWeight);
        int currentWeight = 0;
        
        foreach (var (value, weight) in weightedValues)
        {
            currentWeight += weight;
            if (randomValue < currentWeight)
            {
                return value;
            }
        }
        
        throw new InvalidOperationException("No values provided.");
    }
}
​
// 使用示例 - Medium被选中的概率是Small和Large的2倍
Size randomSize = WeightedEnumRandomizer.RandomValue(
    (Size.Small, 1),
    (Size.Medium, 2),
    (Size.Large, 1)
);
Console.WriteLine(randomSize); // 输出可能为：Medium

using System;
using System.Linq;
​
public enum Animal
{
    Dog,
    Cat,
    Bird,
    Fish
}
​
public static class EnumExtensions
{
    private static Random random = new Random();
    
    public static T Random<T>(this T @enum) where T : Enum
    {
        Array values = Enum.GetValues(typeof(T));
        return (T)values.GetValue(random.Next(values.Length));
    }
}
​
// 使用示例
Animal randomAnimal = default(Animal).Random();
// 或者
Animal anotherRandomAnimal = EnumExtensions.Random(Animal.Dog);
Console.WriteLine(randomAnimal); // 输出可能为：Bird