NET--可绑定可排序列表

/// <summary>
    /// BindingList with sorting feature
    /// </summary>
    /// <typeparam name="T"></typeparam>
    public class SortableBindingList<T> : BindingList<T>
    {
        private bool isSortedCore = true;
        private ListSortDirection sortDirectionCore = ListSortDirection.Ascending;
        private PropertyDescriptor sortPropertyCore = null;
        private string defaultSortItem;
 
        /// <summary>
        /// constructor
        /// </summary>
        public SortableBindingList() : base() { }
 
        /// <summary>
        /// constructor
        /// </summary>
        /// <param name="list"></param>
        public SortableBindingList(IList<T> list) : base(list) { }
 
        protected override bool SupportsSortingCore
        {
            get { return true; }
        }
 
        protected override bool SupportsSearchingCore
        {
            get { return true; }
        }
 
        protected override bool IsSortedCore
        {
            get { return isSortedCore; }
        }
 
        protected override ListSortDirection SortDirectionCore
        {
            get { return sortDirectionCore; }
        }
 
        protected override PropertyDescriptor SortPropertyCore
        {
            get { return sortPropertyCore; }
        }
 
        protected override int FindCore(PropertyDescriptor prop, object key)
        {
            for (int i = 0; i < this.Count; i++)
            {
                if (Equals(prop.GetValue(this[i]), key)) return i;
            }
            return -1;
        }
 
        protected override void ApplySortCore(PropertyDescriptor prop, ListSortDirection direction)
        {
            isSortedCore = true;
            sortPropertyCore = prop;
            sortDirectionCore = direction;
            Sort();
        }
 
        protected override void RemoveSortCore()
        {
            if (isSortedCore)
            {
                isSortedCore = false;
                sortPropertyCore = null;
                sortDirectionCore = ListSortDirection.Ascending;
                Sort();
            }
        }
 
        /// <summary>
        /// Default sort field
        /// </summary>
        public string DefaultSortItem
        {
            get { return defaultSortItem; }
            set
            {
                if (defaultSortItem != value)
                {
                    defaultSortItem = value;
                    Sort();
                }
            }
        }
 
        private void Sort()
        {
            List<T> list = (this.Items as List<T>);
            list.Sort(CompareCore);
            ResetBindings();
        }
 
        private int CompareCore(T o1, T o2)
        {
            int ret = 0;
            if (SortPropertyCore != null)
            {
                ret = CompareValue(SortPropertyCore.GetValue(o1), SortPropertyCore.GetValue(o2), SortPropertyCore.PropertyType);
            }
            if (ret == 0 && DefaultSortItem != null)
            {
                PropertyInfo property = typeof(T).GetProperty(DefaultSortItem, BindingFlags.Public | BindingFlags.GetProperty | BindingFlags.Instance | BindingFlags.IgnoreCase, null, null, new Type[0], null);
                if (property != null)
                {
                    ret = CompareValue(property.GetValue(o1, null), property.GetValue(o2, null), property.PropertyType);
                }
            }
            if (SortDirectionCore == ListSortDirection.Descending) ret = -ret;
            return ret;
        }
 
        private static int CompareValue(object o1, object o2, Type type)
        {
            //这里改成自己定义的比较 
            if (o1 == null)
                return o2 == null ? 0 : -1;
            if (o2 == null)
                return 1;
            if (type.IsPrimitive || type.IsEnum || IsNullablePrimitiveType(type))
                return Convert.ToDouble(o1).CompareTo(Convert.ToDouble(o2));
            if (type == typeof (DateTime) || type == typeof (DateTime?))
                return Convert.ToDateTime(o1).CompareTo(o2);
            return String.Compare(o1.ToString().Trim(), o2.ToString().Trim());
        }
 
        /// <summary>  
        /// 判断是否为基元类型可空类型  
        /// </summary>  
        /// <param name="type">类型</param>  
        /// <returns>是否</returns>  
        public static bool IsNullablePrimitiveType(Type type)
        {
            if (!type.IsGenericType)
            {
                return false;
            }
            //泛型的基础类型是否是基元类型
            if (!type.GetGenericArguments()[0].IsPrimitive)
            {
                return false;
            }
 
            Type genericTypeDefinition = type.GetGenericTypeDefinition();
            return genericTypeDefinition != null && genericTypeDefinition.Equals(typeof (Nullable<>));
        }
    }