/// <summary>
/// 构造函数
/// </summary>
/// <param name="source"></param>
/// <param name="keyselector"></param>
public OrderThenBySequence(数据结构.IEnumerable <TSource> source, 内置委托.Func <TSource, TKey> keyselector, 系统内置接口.IComparer <TKey> comparer)
{
if (source == null)
{
throw new Exception("需要排序的数据源不能为空");
}
if (keyselector == null)
{
throw new Exception("需要排序的字段不能为空");
}
this.comparer = comparer;
this.source = source;
this.keyselector = keyselector;
this.parent = null;//如果是orderby那么就说明只需要创建一个序列，也就没有了父级序列
//如果用户没有定义默认的比较器就使用系统默认的比较器
if (this.comparer == null)
{
数据结构.Comparer <TKey> comparerclass = new Comparer <TKey>();
this.comparer = comparerclass.Default;
}
}
/// <summary>
///当OrderBy之后进行ThenBy的序列的创建的时候调用的方法,接受必须进行OrderBy之后的参数(IOrderThenBy类型的参数)
/// </summary>
/// <param name="afterorderbysource">IOrderThenBy的数据类型</param>
/// <param name="thenbyKeySelector">ThenBy需要执行的方法</param>
/// <returns></returns>
public 数据结构.OrderThenBySequence <TSource, TKey> CreateForThenBy(内置委托.Func <TSource, TKey> thenbyKeySelector, 系统内置接口.IComparer <TKey> comparer)
{
数据结构.OrderThenBySequence <TSource, TKey> thenbysource = new OrderThenBySequence <TSource, TKey>(source, thenbyKeySelector, comparer);
thenbysource.parent = this;//this表示的当前的类，某个类的实例的对象.方法,那么在这个方法中的this就是这个 实例对象
return(thenbysource);
}