/// <summary>
/// Undo 操作。
/// </summary>
public void Undo()
{
try
{
IViCollectionChanged Collection = this.Collection;
switch (this.Action)
{
case NotifyCollectionChangedAction.Add:
if (this.NewItems != null)
{
int count = this.NewItems.Count;
for (int i = 0; i < count; ++i)
{
Collection._RemoveAt(this.NewStartingIndex + i);
}
}
break;
case NotifyCollectionChangedAction.Remove:
if (this.OldItems != null)
{
int count = this.OldItems.Count;
for (int i = 0; i < count; ++i)
{
Collection._InsertAt(this.OldStartingIndex + i, this.OldItems[i]);
}
}
break;
case NotifyCollectionChangedAction.Replace:
if (this.OldItems != null)
{
int count = this.OldItems.Count;
for (int i = 0; i < count; ++i)
{
Collection._SetItem(this.OldStartingIndex + i, this.OldItems[i]);
}
}
break;
}
}
catch (Exception ee)
{
Trace.WriteLine("### [" + ee.Source + "] Exception: " + ee.Message);
Trace.WriteLine("### " + ee.StackTrace);
}
}
public ViCollectionChangedEventArgs(IViCollectionChanged owner, NotifyCollectionChangedEventArgs e)
{
this.Owner = owner;
this.e = e;
}
/// <summary>
/// 观察集合的元素变化。
/// </summary>
/// <param name="collection">集合</param>
/// @warning 集合元素的属性变化不会被观察。
public void ObserveCollectionChanged(IViCollectionChanged collection)
{
collection.CollectionChanged += item_PropertyChanged;
}
