将IEnumerable <IEnumerable <T >>转换为List <List <T >>

using System;
using System.Collections.Generic;
using System.Linq;

public class Program
{
    public static void Main()
    {
        IEnumerable<IEnumerable<int>> nestedCollection = new List<IEnumerable<int>>
        {
            new List<int> { 1, 2, 3 },
            new List<int> { 4, 5, 6 },
            new List<int> { 7, 8, 9 }
        };

        List<List<int>> convertedList = nestedCollection.Select(innerCollection => innerCollection.ToList()).ToList();

        foreach (List<int> innerList in convertedList)
        {
            foreach (int value in innerList)
            {
                Console.Write(value + " ");
            }
            Console.WriteLine();
        }
    }
}

1 2 3
4 5 6
7 8 9