我有一个元素数组,其中元素具有Flagged布尔值.
1 flagged 2 not flagged 3 not flagged 4 flagged 5 not flagged 6 not flagged 7 not flagged 8 flagged 9 not flagged
我想根据标记的指标将其分解为数组
输出>
array 1 {1,2,3}
array 2 {4,5,6,7}
array 3 {8,9}
解决方法
Linq没有这方面的操作符,但我编写了一个你可以使用的扩展方法(在提交到
MoreLinq的过程中,你也应该检查)：
使用下面的运算符,你会写：
var result =
items.Segment( (item,prevItem,idx) => item.Flagged )
.Select( seq => seq.ToArray() ) // converts each sequence to an array
.ToList();
public static IEnumerable<IEnumerable<T>> Segment<T>(IEnumerable<T> sequence,Func<T,T,int,bool> newSegmentIdentifier)
{
var index = -1;
using (var iter = sequence.GetEnumerator())
{
var segment = new List<T>();
var prevItem = default(T);
// ensure that the first item is always part
// of the first segment. This is an intentional
// behavior. Segmentation always begins with
// the second element in the sequence.
if (iter.MoveNext())
{
++index;
segment.Add(iter.Current);
prevItem = iter.Current;
}
while (iter.MoveNext())
{
++index;
// check if the item represents the start of a new segment
var isNewSegment = newSegmentIdentifier(iter.Current,index);
prevItem = iter.Current;
if (!isNewSegment)
{
// if not a new segment,append and continue
segment.Add(iter.Current);
continue;
}
yield return segment; // yield the completed segment
// start a new segment...
segment = new List<T> { iter.Current };
}
// handle the case of the sequence ending before new segment is detected
if (segment.Count > 0)
yield return segment;
}
}
