如何在.NET中解析union和list类型的值？

List<int> numbers = new List<int> { 1, 2, 3, 4, 5 };

enum Colors
{
    Red,
    Green,
    Blue
}

Colors color = Colors.Red;

switch (color)
{
    case Colors.Red:
        Console.WriteLine("The color is red.");
        break;
    case Colors.Green:
        Console.WriteLine("The color is green.");
        break;
    case Colors.Blue:
        Console.WriteLine("The color is blue.");
        break;
    default:
        Console.WriteLine("The color is not recognized.");
        break;
}

List<int> numbers = new List<int> { 1, 2, 3, 4, 5 };

for (int i = 0; i< numbers.Count; i++)
{
    Console.WriteLine(numbers[i]);
}

List<int> numbers = new List<int> { 1, 2, 3, 4, 5 };

foreach (int number in numbers)
{
    Console.WriteLine(number);
}

List<int> numbers = new List<int> { 1, 2, 3, 4, 5 };

var evenNumbers = from number in numbers
                  where number % 2 == 0
                  orderby number descending
                  select number;

foreach (int evenNumber in evenNumbers)
{
    Console.WriteLine(evenNumber);
}