/// <summary>
/// 索引器根据键TKey获取对应的组
/// </summary>
/// <param name="key"></param>
/// <returns></returns>
internal IEnumerable <TElement> this[TKey key]
{
get {
MyGrouping <TKey, TElement> grouping = GetGrouping(key, false);
if (grouping != null)
{
return(grouping);
}
return(null);
}
}
public 数据结构.IEnumerable <系统内置接口.IGrouping <TKey, TElement> > GetPerGroup()
{
MyList <系统内置接口.IGrouping <TKey, TElement> > list = new MyList <系统内置接口.IGrouping <TKey, TElement> >();
MyGrouping <TKey, TElement> g = lastGroup;
if (g != null)
{
do
{
g = g.next;
list.Add(g);
} while (g != lastGroup);
}
return(list);
}
/// <summary>
/// 根据键值来获取对应的组或者创建对应的组
/// </summary>
/// <param name="key">键值</param>
/// <param name="create">是否创建新的组</param>
/// <returns></returns>
internal 数据结构.MyGrouping <TKey, TElement> GetGrouping(TKey key, bool create)
{
//1.根据每个对象的分组字段的值计算hashcode
//2.根据hashcode获取这个对象在grouping[]中的索引
//3.判断这个索引的位置是否存在元素(①：存在元素判断hashcode的值并根据比较器比较Key和当前的Key是否相等②:不存在元素，那么就创建一个新的组)
//int hashCode = InitialHashCode(key);
int hashCode = MyInitialHashCode(key);
int index = hashCode % groupings.Length;
for (MyGrouping <TKey, TElement> g = groupings[index]; g != null; g = g.hashNext)
{
if (g != null)
{
if (g.hashcode == hashCode && comparer.Equal(g.Key, key))
{
return(g);
}
}
}
//在已有的存在的grouping的数组中都没有找到就创建对应的Grouping
if (create)
{
//所有具有相同的HashCode、不同键的值得数据形成一条单链表
//调用MyGrouping类的默认的容量来初始化Telement[] 数组的大小
MyGrouping <TKey, TElement> newGrouping = new MyGrouping <TKey, TElement>();
newGrouping.key = key;
newGrouping.hashcode = hashCode;
newGrouping.hashNext = groupings[index];
groupings[index] = newGrouping;
//使所有的元素形成一条循环链表
if (lastGroup == null)
{
newGrouping.next = newGrouping;
lastGroup = newGrouping;
}
else
{
newGrouping.next = lastGroup.next;
lastGroup.next = newGrouping;
lastGroup = newGrouping;
}
this.count++;
return(newGrouping);
}
return(null);
}
/// <summary>
/// 对已经分完组的每一个组进行统计操作
/// </summary>
/// <typeparam name="TResult"></typeparam>
/// <param name="resultselector"></param>
/// <returns></returns>
#warning 这个地方还可以改进(换成自己的集合的返回的类型)
public System.Collections.Generic.IEnumerable <TResult> StaticResult <TResult>(Func <TKey, System.Collections.Generic.IEnumerable <TElement>, TResult> resultselector)
{
MyGrouping <TKey, TElement> g = lastGroup;
if (g != null)
{
do
{
g = g.next;
if (g.count != g.temp.Length)
{
Array.Resize <TElement>(ref g.temp, g.count);
}
yield return(resultselector(g.key, g.temp));
#warning 这个地方为什么是不等于？
} while (g != lastGroup);
//while (g == lastGroup);
}
}
