winform datagridview 绑定泛型集合变得不支持排序的解决方案

案例：

　　环境：Winform程序

　　控件：Datagridview

　　现象：Datagridview控件绑定到List<T>泛型数据上不支持排序

　　　　　Datagridview控件绑定到DataTable上可以支持排序

　　结论：泛型会使Datagridview失去排序特性

　　解决：实现BindingList<T>接口

　　实现代码：

　　

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Reflection;
using System.Text;

namespace HOET.Plugins.Orders.Model
{
    /// <summary>
    /// 泛型会失去DataTable特性，DataGridView绑定List<T>后不支持排序
    /// </summary>
    /// <typeparam name="T"></typeparam>
    class SortableBindingList<T> : BindingList<T>
    {
        private bool isSortedCore = true;
        private ListSortDirection sortDirectionCore = ListSortDirection.Ascending;
        private PropertyDescriptor sortPropertyCore = null;
        private string defaultSortItem;

        public SortableBindingList() : base() { }

        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();
            }
        }

        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)
        {
            if(o1 == null)
            {
                return o2 == null ? 0 : -1;
            }
            else if(o2 == null)
            {
                return 1;
            }
            else if(type == typeof(char))
            {
                return String.Compare(o1.ToString().Trim(), o2.ToString().Trim());
            }
            else if (type.IsEnum ||type.IsPrimitive)
            {
                return Convert.ToDouble(o1).CompareTo(Convert.ToDouble(o2));
            }
            else if(type == typeof(DateTime))
            {
                return Convert.ToDateTime(o1).CompareTo(o2);
            }
            else
            {
                return String.Compare(o1.ToString().Trim(), o2.ToString().Trim());
            }
        }
    }
}