任意の要素数ごとに分割した列挙を取得する

EnumerableEx.cs

using System;
using System.Collections.Generic;

namespace kuchikios.Qiita
{
    public static class EnumerableEx
    {
        public static IEnumerable<TValue[ ]> Split<TValue>( this IEnumerable<TValue> source, int blockCount, bool includeLastFractionBlock = false )
        {
            if ( default( IEnumerable<TValue> ) == source ) throw new ArgumentNullException( "source", "参照がありません" );
            if ( 1 > blockCount ) throw new ArgumentOutOfRangeException( "blockCount", "範囲外の値です" );

            var values = new List<TValue>( );
            foreach ( var value in source )
            {
                values.Add( value );
                if ( blockCount == values.Count )
                {
                    yield return values.ToArray( );
                    values.Clear( );
                }
            }
            if ( 0 < values.Count )
            {
                if ( blockCount == values.Count || includeLastFractionBlock )
                {
                    yield return values.ToArray( );
                }
                values.Clear( );
            }
        }
    }
}