/// <summary>
/// 构造函数
/// </summary>
/// <param name="comparer"></param>
internal MyLookup(系统内置接口.IEqualityComparer <TKey> comparer)
{
//如果没有传入比较器，那么就调用默认的比较器，默认的比较器是要根据传入的TKey的类型来去创建
if (comparer == null)
{
数据结构.EqualityComparer <TKey> defaultcomparer = new EqualityComparer <TKey>();
this.comparer = defaultcomparer.Default;
}
//设置grouping[]的默认的初始的大小
groupings = new MyGrouping <TKey, TElement> [7];
}
public static 系统内置接口.ILookup <TKey, TSource> ToLookup <TKey, TSource>(this IEnumerable <TSource> source, 内置委托.Func <TSource, TKey> keyselector, 系统内置接口.IEqualityComparer <TKey> comparer)
{
MyLookup <TKey, TSource> lookup = new MyLookup <TKey, TSource>(comparer);
lookup.Create(source, keyselector, 数据结构.IdentityFunction <TSource> .Instance);
return(lookup);
}
/// <summary>
/// 基本的ToLookup方法
/// </summary>
/// <typeparam name="TKey">分组的键</typeparam>
/// <typeparam name="TSource">数据源中的每一个实体</typeparam>
/// <typeparam name="TElement">筛选后的数据</typeparam>
/// <param name="source">数据源</param>
/// <param name="keyselector">选择分组键的方法</param>
/// <param name="elementselector">筛选要选取的数据</param>
/// <param name="comparer">用户定义的比较器</param>
/// <returns></returns>
public static 系统内置接口.ILookup <TKey, TElement> ToLookup <TKey, TSource, TElement>(this IEnumerable <TSource> source, 内置委托.Func <TSource, TKey> keyselector, 内置委托.Func <TSource, TElement> elementselector, 系统内置接口.IEqualityComparer <TKey> comparer)
{
MyLookup <TKey, TElement> lookup = new MyLookup <TKey, TElement>(comparer);
lookup.Create(source, keyselector, elementselector);
return(lookup);
}
public static 数据结构.IEnumerable <系统内置接口.IGrouping <TKey, TSource> > GroupBy <TSource, TKey>(this IEnumerable <TSource> source, 内置委托.Func <TSource, TKey> keyselector, 内置委托.Func <TSource, TSource> elementselector, 系统内置接口.IEqualityComparer <TKey> comparer)
{
MyLookup <TKey, TSource> lookup = new MyLookup <TKey, TSource>(comparer);
lookup.Create(source, keyselector, elementselector);
return(lookup.GetPerGroup());
}
