ChoUtility.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ChoEazyCopy
{
    public static class ChoUtility
    {
        public static void Move<T>(this List<T> list, int oldIndex, int newIndex)
        {
            var item = list[oldIndex];

            list.RemoveAt(oldIndex);

            if (newIndex > oldIndex) newIndex--;
            // the actual index could have shifted due to the removal

            list.Insert(newIndex, item);
        }

        public static void Move<T>(this List<T> list, T item, int newIndex)
        {
            if (item != null)
            {
                var oldIndex = list.IndexOf(item);
                if (oldIndex > -1)
                {
                    list.RemoveAt(oldIndex);

                    if (newIndex > oldIndex) newIndex--;
                    // the actual index could have shifted due to the removal

                    list.Insert(newIndex, item);
                }
            }

        }
    }
}