Learning/Mysql-example/Util/SortableBindingList.cs

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

namespace Mysql_example.Util
{
    public class SortableBindingList<T> : BindingList<T>
    {
        private bool IsSorted { get; set; }
        private ListSortDirection SortDirection { get; set; }
        private PropertyDescriptor SortProperty { get; set; }
        private readonly List<T>? _originalData;
        protected override bool SupportsSortingCore
        {
            get
            {
                return true;
            }
        }
        protected override ListSortDirection SortDirectionCore
        {
            get
            {
                return SortDirection;
            }
        }
        protected override PropertyDescriptor SortPropertyCore
        {
            get
            {
                return SortProperty;
            }
        }
        protected override void ApplySortCore(PropertyDescriptor PDsc, ListSortDirection Direction)
        {
            List<T> items = Items as List<T>;
            if (items is null)
            {
                IsSorted = false;
            }
            else
            {
                var PCom = new PCompare<T>(PDsc.Name, Direction);
                items.Sort(PCom);
                IsSorted = true;
                SortDirection = Direction;
                SortProperty = PDsc;
            }
            OnListChanged(new ListChangedEventArgs(ListChangedType.Reset, -1));
        }
        protected override bool IsSortedCore
        {
            get
            {
                return IsSorted;
            }
        }
        protected override void RemoveSortCore()
        {
            IsSorted = false;
        }
        #region  Constructors 
        public SortableBindingList(ICollection<T> list) : base((IList<T>)list)
        {
        }
        public SortableBindingList() : base()
        {
        }
        #endregion
        #region  Property comparer 
        private class PCompare<Type> : IComparer<T> where Type : T
        {
            private PropertyInfo PropInfo { get; set; }
            private ListSortDirection SortDir { get; set; }
            internal PCompare(string SortProperty, ListSortDirection SortDirection)
            {
                PropInfo = typeof(T).GetProperty(SortProperty);
                SortDir = SortDirection;
            }
            internal int Compare(T x, T y)
            {
                return SortDir == ListSortDirection.Ascending ? Comparer.Default.Compare(PropInfo.GetValue(x, null), PropInfo.GetValue(y, null)) : Comparer.Default.Compare(PropInfo.GetValue(y, null), PropInfo.GetValue(x, null));
            }
            int IComparer<T>.Compare(T x, T y) => Compare(x, y);
        }
        #endregion
    }
}