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

Posted 2021-03-25 lonelyxmas

原文: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：

　　

  1 using System;
  2 using System.Collections.Generic;
  3 using System.ComponentModel;
  4 using System.Linq;
  5 using System.Reflection;
  6 using System.Text;
  7 
  8 namespace HOET.Plugins.Orders.Model
  9 {
 10     /// <summary>
 11     /// 泛型会失去DataTable特性，DataGridView绑定List<T>后不支持排序
 12     /// </summary>
 13     /// <typeparam name="T"></typeparam>
 14     class SortableBindingList<T> : BindingList<T>
 15     {
 16         private bool isSortedCore = true;
 17         private ListSortDirection sortDirectionCore = ListSortDirection.Ascending;
 18         private PropertyDescriptor sortPropertyCore = null;
 19         private string defaultSortItem;
 20 
 21         public SortableBindingList() : base() { }
 22 
 23         public SortableBindingList(IList<T> list) : base(list) { }
 24 
 25         protected override bool SupportsSortingCore
 26         {
 27             get { return true; }
 28         }
 29 
 30         protected override bool SupportsSearchingCore
 31         {
 32             get { return true; }
 33         }
 34 
 35         protected override bool IsSortedCore
 36         {
 37             get { return isSortedCore; }
 38         }
 39 
 40         protected override ListSortDirection SortDirectionCore
 41         {
 42             get { return sortDirectionCore; }
 43         }
 44 
 45         protected override PropertyDescriptor SortPropertyCore
 46         {
 47             get { return sortPropertyCore; }
 48         }
 49 
 50         protected override int FindCore(PropertyDescriptor prop, object key)
 51         {
 52             for(int i = 0; i < this.Count; i++)
 53             {
 54                 if(Equals(prop.GetValue(this[i]),key))
 55                 {
 56                     return i;
 57                 }
 58             }
 59 
 60             return -1;
 61         }
 62 
 63         protected override void ApplySortCore(PropertyDescriptor prop, ListSortDirection direction)
 64         {
 65             isSortedCore = true;
 66             sortPropertyCore = prop;
 67             sortDirectionCore = direction;
 68             Sort();
 69         }
 70 
 71         protected override void RemoveSortCore()
 72         {
 73             if(isSortedCore)
 74             {
 75                 isSortedCore = false;
 76                 sortPropertyCore = null;
 77                 sortDirectionCore = ListSortDirection.Ascending;
 78                 Sort();
 79             }
 80         }
 81 
 82         public string DefaultSortItem
 83         {
 84             get
 85             {
 86                 return defaultSortItem;
 87             }
 88             set
 89             {
 90                 if(defaultSortItem != value)
 91                 {
 92                     defaultSortItem = value;
 93                     Sort();
 94                 }
 95             }
 96         }
 97 
 98         private void Sort()
 99         {
100             List<T> list = this.Items as List<T>;
101             list.Sort(CompareCore);
102             ResetBindings();
103         }
104 
105         private int CompareCore(T o1, T o2)
106         {
107             int ret = 0;
108             if(SortPropertyCore != null)
109             {
110                 ret = CompareValue(SortPropertyCore.GetValue(o1), SortPropertyCore.GetValue(o2), SortPropertyCore.PropertyType);
111             }
112             if(ret == 0 && DefaultSortItem != null)
113             {
114                 PropertyInfo property = typeof(T).GetProperty(DefaultSortItem, BindingFlags.Public | BindingFlags.GetProperty | BindingFlags.Instance | BindingFlags.IgnoreCase, null, null, new Type[0], null);
115                 if(property != null)
116                 {
117                     ret = CompareValue(property.GetValue(o1, null), property.GetValue(o2, null), property.PropertyType);
118                 }
119             }
120             if(SortDirectionCore == ListSortDirection.Descending)
121             {
122                 ret = -ret;
123             }
124 
125             return ret;
126         }
127 
128         private static int CompareValue(object o1, object o2, Type type)
129         {
130             if(o1 == null)
131             {
132                 return o2 == null ? 0 : -1;
133             }
134             else if(o2 == null)
135             {
136                 return 1;
137             }
138             else if(type == typeof(char))
139             {
140                 return String.Compare(o1.ToString().Trim(), o2.ToString().Trim());
141             }
142             else if (type.IsEnum ||type.IsPrimitive)
143             {
144                 return Convert.ToDouble(o1).CompareTo(Convert.ToDouble(o2));
145             }
146             else if(type == typeof(DateTime))
147             {
148                 return Convert.ToDateTime(o1).CompareTo(o2);
149             }
150             else
151             {
152                 return String.Compare(o1.ToString().Trim(), o2.ToString().Trim());
153             }
154         }
155     }
156 }

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