因为平时使用 System.Collections.CollectionBase 时候发现有些不足，故而作了一个扩展的 CollectionBaseEx，代码如下，因为注释较多，故不再解释。
/**//// <summary>
/// 增强的 CollectionBase ，支持排序，和更多的通知
/// </summary>
public class CollectionBaseEx : IList 
{ private ArrayList m_InnerList; private bool m_Duplicated; // 是否允许重复元素 private bool m_Sorted; // 是否允许排序 private IComparer m_Comparer; // 排序时候使用的比较器 private bool m_SingleCheck; // 是否在处理时候要处理单个元素，引发Include/Exclude事件
/**//// <summary> /// 默认构造函数
/// </summary> protected CollectionBaseEx() { m_InnerList = new ArrayList(); m_Duplicated = true; m_Sorted = false; m_Comparer = System.Collections.Comparer.Default; m_SingleCheck = false; } /**//// <summary> /// 构造函数 /// </summary> /// <param name="duplicated">是否允许重复元素</param> /// <param name="singleCheck">是否对每一个元素进行检查并发出通知</param> /// <param name="sorted">对值进行排序</param> /// <param name="comparer">比较器</param> protected CollectionBaseEx(bool duplicated, bool singleCheck, bool sorted, IComparer comparer) : this() { m_Duplicated = duplicated; m_Sorted = sorted; m_Comparer = comparer; m_SingleCheck = singleCheck; } /**//// <summary> /// 操作接口，能够触发各种通知 /// </summary> protected IList List { get { return this; } } /**//// <summary> /// 实际存放数据的容器 /// </summary> protected ArrayList InnerList { get { return m_InnerList; } set { if (value == null) throw new ArgumentNullException("value can not be null", "value"); m_InnerList = value; } } /**//// <summary> /// 允许重复元素 /// </summary> protected bool Duplicated { get { return m_Duplicated; } set { m_Duplicated = value; } } /**//// <summary> /// 排序 /// </summary> protected bool Sorted { get { return m_Sorted; } set { m_Sorted = value; } } /**//// <summary> /// 对每一个元素进行检查并发出通知 /// </summary> protected bool SingleCheck { get { return m_SingleCheck; } set { m_SingleCheck = value; } } /**//// <summary> /// 比较器 /// </summary> protected IComparer Comparer { get { return m_Comparer; } set { m_Comparer = value; } } callback#region callback /**//// <summary> /// 清除所有元素之前的通知 /// </summary> protected virtual void OnClear(){} /**//// <summary> /// 所有元素清除成功之后的通知 /// </summary> protected virtual void OnClearComplete(){} /**//// <summary> /// 插入元素之前的通知 /// </summary> /// <param name="index">元素插入位置</param> /// <param name="value">插入的值</param> protected virtual void OnInsert(int index, object value){} /**//// <summary> /// 元素插入成功之后的通知 /// </summary> /// <param name="index">元素插入位置</param> /// <param name="value">插入的值</param> protected virtual void OnInsertComplete(int index, object value){} /**//// <summary> /// 删除元素之前的通知 /// </summary> /// <param name="index">要删除元素的位置</param> /// <param name="value">要删除的元素</param> protected virtual void OnRemove(int index, object value){} /**//// <summary> /// 删除元素之后的通知 /// </summary> /// <param name="index">要删除元素的位置</param> /// <param name="value">要删除的元素</param> protected virtual void OnRemoveComplete(int index, object value){} /**//// <summary> /// 设置元素的值之前的通知 /// </summary> /// <param name="index">元素的位置</param> /// <param name="oldValue">该位置的当前的值</param> /// <param name="newValue">将要存放到该位置的新值</param> /// <remarks>如果<see cref="Sorted"/>为真，则设置成功之后的元素会移动到正确的位置上去</remarks> protected virtual void OnSet(int index, object oldValue, object newValue){} /**//// <summary> /// 设置元素的值成功之后的通知 /// </summary> /// <param name="index">元素位置</param> /// <param name="oldValue">该位置以前的值</param> /// <param name="newValue">该位置当前的值</param> /// <remarks>如果<see cref="Sorted"/>为真，则设置成功之后的元素会移动到正确的位置上去</remarks> protected virtual void OnSetComplete(int index, object oldValue, object newValue){} /**//// <summary> /// 通知对元素进行正确性检查 /// </summary> /// <param name="value">将要存放的值</param> protected virtual void OnValidate(object value){} /**//// <summary> /// 将要把元素存放到容器之前的通知 /// </summary> /// <param name="value">将要存放的值</param> protected virtual void OnInclude(object value){} /**//// <summary> /// 将要把元素从容器中脱离之前的通知 /// </summary> /// <param name="value">将要脱离容器的值</param> protected virtual void OnExclude(object value){} #endregion internal logic#region internal logic private void BeforeClear() { if( m_SingleCheck ) { int index = 0; try { while( index < m_InnerList.Count) { OnExclude(m_InnerList[index]); ++ index; } } catch(Exception) { while( --index >= 0 ) OnInclude(m_InnerList[index]); throw; } } OnClear(); } private void AfterClearComplete() { OnClearComplete(); } private void BeforeInsert(int index, object value) { if( m_Sorted ) throw new InvalidOperationException("排序状态下不能使用"); if( this.m_SingleCheck ) OnInclude(value); OnInsert(index, value); } private void AfterInsertComplete(int index, object value) { OnInsertComplete(index, value); } private void BeforeRemove(int index, object value) { if( m_SingleCheck ) OnExclude(value); OnRemove(index, value); } private void AfterRemoveComplete(int index, object value) { OnRemoveComplete(index, value); } private void BeforeSet(int index, object oldValue, object newValue) { if( m_SingleCheck ) OnInclude(newValue); OnSet(index, oldValue, newValue); } private void AfterSetComplete(int index, object oldValue, object newValue) { if( m_SingleCheck ) OnExclude(oldValue); OnSetComplete(index, oldValue, newValue); } private void CheckValidate(object value) { if (value == null) throw new ArgumentNullException("value can not be null", "value"); if( !Duplicated && (( !m_Sorted && m_InnerList.IndexOf(value) != -1 ) || (m_Sorted && m_InnerList.BinarySearch(value, m_Comparer) >= 0) )) throw new ArgumentException("object exists"); OnValidate(value); } #endregion IList 成员#region IList 成员 bool IList.IsReadOnly { get { return m_InnerList.IsReadOnly; } } object IList.this[int index] { get { return m_InnerList[index]; } set { CheckValidate(value); object old = m_InnerList[index]; this.BeforeSet(index, old, value); m_InnerList[index] = value; try { this.AfterSetComplete(index, old, value); if( m_Sorted ) // 移动到正确位置 { m_InnerList.RemoveAt(index); int pos = m_InnerList.BinarySearch(value, m_Comparer); if( pos < 0 ) pos = ~pos; m_InnerList.Insert(pos, value); } } catch (Exception) { m_InnerList[index] = old; throw; } } } public void RemoveAt(int index) { object obj = m_InnerList[index]; this.BeforeRemove(index, obj); m_InnerList.RemoveAt(index); this.AfterRemoveComplete(index, obj); } void IList.Insert(int index, object value) { CheckValidate(value); this.BeforeInsert(index, value); m_InnerList.Insert(index, value); try { this.AfterInsertComplete(index, value); } catch (Exception) { m_InnerList.RemoveAt(index); throw; } } void IList.Remove(object value) { int index = m_InnerList.IndexOf(value); if( index < 0 ) throw new ArgumentException("object not found"); this.BeforeRemove(index, value); m_InnerList.Remove(value); this.AfterRemoveComplete(index, value); } bool IList.Contains(object value) { return m_InnerList.Contains(value); } public void Clear() { this.BeforeClear(); m_InnerList.Clear(); this.AfterClearComplete(); } int IList.IndexOf(object value) { return m_InnerList.IndexOf(value); } int IList.Add(object value) { CheckValidate(value); int index = m_InnerList.Count; if( m_Sorted ) { index = m_InnerList.BinarySearch(value, m_Comparer); if( index < 0 ) index = ~index; } this.BeforeInsert(index, value); if( !m_Sorted ) index = m_InnerList.Add(value); else m_InnerList.Insert(index, value); try { this.AfterInsertComplete(index, value); } catch (Exception) { m_InnerList.RemoveAt(index); throw; } return index; } bool IList.IsFixedSize { get { return m_InnerList.IsFixedSize; } } #endregion ICollection 成员#region ICollection 成员 bool ICollection.IsSynchronized { get { return m_InnerList.IsSynchronized; } } public int Count { get { return m_InnerList.Count; } } void ICollection.CopyTo(Array array, int index) { m_InnerList.CopyTo(array, index); } object ICollection.SyncRoot { get { return m_InnerList.SyncRoot; } } #endregion IEnumerable 成员#region IEnumerable 成员 public IEnumerator GetEnumerator() { return m_InnerList.GetEnumerator(); } #endregion public IEnumerator GetEnumerator(int index, int count) { return m_InnerList.GetEnumerator(index, count); } }
