// 将 index + 1 位置的内容提取出来，当前位置改到 index + 1
public void Forward(ListView list, T state)
{
if (this.Index + 1 >= this.Count)
{
return;
}
DelaySet(list, state, this.Index);
list.Items.Clear();
this.Index++;
ListItems <T> items = this[this.Index];
foreach (ListViewItem item in items)
{
list.Items.Add(item);
}
if (this.StateChanged != null)
{
StateChangedEventArgs e = new StateChangedEventArgs();
e.State = items.State;
this.StateChanged(this, e);
}
}
// 在末尾增加一个记忆
public void Add(ListView list,
T state,
bool bDelay = false)
{
while (this.Count > this.Index + 1)
{
this.RemoveAt(this.Index + 1);
}
ListItems <T> items = new ListItems <T>();
items.State = state;
if (bDelay == false)
{
foreach (ListViewItem item in list.Items)
{
items.Add(item);
}
}
else
{
items.Delay = true;
}
this.Add(items);
this.Index++;
}
// 刷新当前记忆
public void Refresh(ListView list,
T state,
bool bDelay = false)
{
#if NO
if (this.Index + 1 < this.Count)
{
ListItems <T> items = this[this.Index + 1];
items.State = state;
if (bDelay == false)
{
items.Clear();
foreach (ListViewItem item in list.Items)
{
items.Add(item);
}
}
else
{
// 即便以前有内容，也要清除，以便以后可以延迟装载
items.Clear();
items.Delay = true;
}
}
#endif
if (this.Index < this.Count && this.Index != -1)
{
ListItems <T> items = this[this.Index];
items.State = state;
if (bDelay == false)
{
items.Clear();
foreach (ListViewItem item in list.Items)
{
items.Add(item);
}
}
else
{
// 即便以前有内容，也要清除，以便以后可以延迟装载
items.Clear();
items.Delay = true;
}
}
}
void DelaySet(ListView list, T state, int index)
{
// 滞后加入当前事项
if (index < this.Count)
{
ListItems <T> items = this[index];
if (items.Delay == true)
{
// 滞后加入
items.State = state;
items.Clear();
foreach (ListViewItem item in list.Items)
{
items.Add(item);
}
items.Delay = false;
}
}
}
// 看看是否已经为滞后，需要补充加入
public void EnsureAdd(ListView list, T state)
{
if (this.Index < 0 || this.Index >= this.Count)
{
return;
}
#if NO
ListItems <T> items = this[this.Index];
if (items.Delay == true)
{
// 滞后加入
items.State = state;
items.Clear();
foreach (ListViewItem item in list.Items)
{
items.Add(item);
}
items.Delay = false;
}
#endif
DelaySet(list, state, this.Index);
}