C# 集合扩展快速排序算法

  /// <summary>
    /// 对集合进行排序，如
    /// List<Person> users=new List<Person>(){.......}
    /// ListSorter.SortList<list<Person>,Person>( users,"Age",SortDirection.Ascending);
    /// </summary>
    public static class ListUtil
    {
        public static void SortList<TCollection, TItem>(this TCollection list, string property, SortDirection direction) where TCollection : IList<TItem>
        {
            PropertyInfo[] propertyinfos = typeof(TItem).GetProperties();
            foreach (PropertyInfo propertyinfo in propertyinfos)
            {
                if (propertyinfo.Name == property)          //取得指定的排序属性
                {
                    QuickSort<TCollection, TItem>(list, 0, list.Count - 1, propertyinfo, direction);
                }
            }
        }
        /// <summary>
        /// 快速排序算法
        /// </summary>
        /// <typeparam name="TCollection">集合类型，需要实现Ilist<T>集合</typeparam>
        /// <typeparam name="TItem">集合中对象的类型</typeparam>
        /// <param name="list">集合对象</param>
        /// <param name="left">起始位置，从0开始</param>
        /// <param name="right">终止位置</param>
        /// <param name="propertyinfo">集合中对象的属性，属性必须要实现IComparable接口</param>
        /// <param name="direction">排序类型（升序或降序）</param>
        private static void QuickSort<TCollection, TItem>(TCollection list, int left, int right, PropertyInfo propertyinfo, SortDirection direction) where TCollection : IList<TItem>
        {
            if (left < right)
            {
                int i = left, j = right;
                TItem key = list[left];
                while (i < j)
                {
                    if (direction == SortDirection.Ascending)
                    {
                        while (i < j && ((IComparable)propertyinfo.GetValue(key, null)).CompareTo((IComparable)propertyinfo.GetValue(list[j], null)) < 0)
                        {
                            j--;
                        }
                        if (i < j)
                        {
                            list[i] = list[j];
                            i++;
                        }

                        while (i < j && ((IComparable)propertyinfo.GetValue(key, null)).CompareTo((IComparable)propertyinfo.GetValue(list[i], null)) > 0)
                        {
                            i++;
                        }
                        if (i < j)
                        {
                            list[j] = list[i];
                            j--;
                        }
                        list[i] = key;
                    }
                    else
                    {
                        while (i < j && ((IComparable)propertyinfo.GetValue(key, null)).CompareTo((IComparable)propertyinfo.GetValue(list[j], null)) > 0)
                        {
                            j--;
                        }
                        if (i < j)
                        {
                            list[i] = list[j];
                            i++;
                        }

                        while (i < j && ((IComparable)propertyinfo.GetValue(key, null)).CompareTo((IComparable)propertyinfo.GetValue(list[i], null)) < 0)
                        {
                            i++;
                        }
                        if (i < j)
                        {
                            list[j] = list[i];
                            j--;
                        }
                        list[i] = key;
                    }
                }
                //执行递归调用 
                QuickSort<TCollection, TItem>(list, left, i - 1, propertyinfo, direction);
                QuickSort<TCollection, TItem>(list, i + 1, right, propertyinfo, direction);
            }
        }
    }
    /// <summary>
    /// 排序类型
    /// </summary>
    public enum SortDirection
    {
        Ascending,
        Descending
    }

 

static void SortList<TCollection, TItem>(params...)

static void QuickSort<TCollection, TItem>(params...) 

两个函数摘自http://www.cnblogs.com/sosoft博客，我直接将算法扩展给了List<T>类

测试：

  static void  Main(){  
     Console.WriteLine("\r\n=======List<T>快速排序========");
            List<Person> list2 = new List<Person>()
            {
                new Person { Name = "1", Age = 1 },
                new Person { Name = "2", Age = 2 },
                new Person { Name = "20", Age = 20 },
                new Person { Name = "200", Age = 200 },
                new Person { Name = "-1", Age = -1 },
                new Person { Name = "-2", Age = -2 },
                new Person { Name = "0", Age = 0 },
            };

            list2.SortList<List<Person>, Person>("Age", SortDirection.Descending);

            foreach (var temp in list2)
            {
                Console.Write(temp.Name + " ");
            }
            Console.ReadLine();
}
  
public  class Person
    {
        public string Name { get; set; }

        public int Age { get; set; }
    }