为BindingList添加Sort

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最近在优化WPF性能时，发现在特定条件下BindingList比ObservableCollection性能更高，因为它提供Disable/Enable 更改通知的方法。这样我们可以不需要很频繁的通知UI去更新，而是等所有操作都做完后再通知。

然而，默认的BindingList不支持Sort，需要我们实现。

 public class SortableBindingList<T> : BindingList<T>    {        // Fields        private bool isSorted;        private ListSortDirection listSortDirection;        private PropertyDescriptor propertyDescriptor;         // Methods        public SortableBindingList()        {        }         public SortableBindingList(IList<T> list)            : this()        {            base.Items.Clear();            foreach (T local in list)            {                base.Add(local);            }        }         protected override void ApplySortCore(PropertyDescriptor prop, ListSortDirection direction)        {            (base.Items as List<T>).Sort(this.GetComparisionDelegate(prop, direction));        }         private Comparison<T> GetComparisionDelegate(PropertyDescriptor propertyDescriptor, ListSortDirection direction)        {            return delegate(T t1, T t2)            {                int num2;                ((SortableBindingList<T>)this).propertyDescriptor = propertyDescriptor;                ((SortableBindingList<T>)this).listSortDirection = direction;                ((SortableBindingList<T>)this).isSorted = true;                int num = (direction == ListSortDirection.Ascending) ? 1 : -1;                if (propertyDescriptor.PropertyType == typeof(string))                {                    num2 = StringComparer.CurrentCulture.Compare(propertyDescriptor.GetValue(t1), propertyDescriptor.GetValue(t2));                }                else                {                    num2 = Comparer.Default.Compare(propertyDescriptor.GetValue(t1), propertyDescriptor.GetValue(t2));                }                return (num * num2);            };        }         protected override void RemoveSortCore()        {            this.isSorted = false;            this.propertyDescriptor = base.SortPropertyCore;            this.listSortDirection = base.SortDirectionCore;        }         // Properties        protected override bool IsSortedCore        {            get            {                return this.isSorted;            }        }         protected override ListSortDirection SortDirectionCore        {            get            {                return this.listSortDirection;            }        }         protected override PropertyDescriptor SortPropertyCore        {            get            {                return this.propertyDescriptor;            }        }         protected override bool SupportsSortingCore        {            get            {                return true;            }        }    }

调用RaiseListChangedEvents = false 或者RaiseListChangedEvents = true来控制更改通知，

调用ResetBindings（）来全部更新， 或者ResetItem（index）来更新指定索引