我试图将一个列表拆分为一系列较小的列表。

我的问题:我的拆分列表功能没有将它们拆分为正确大小的列表。它应该把它们分成大小为30的列表,但它却把它们分成大小为114的列表?

如何让我的函数将一个列表分割成X个大小为30或更小的列表?

public static List<List<float[]>> splitList(List <float[]> locations, int nSize=30) 
{       
    List<List<float[]>> list = new List<List<float[]>>();

    for (int i=(int)(Math.Ceiling((decimal)(locations.Count/nSize))); i>=0; i--) {
        List <float[]> subLocat = new List <float[]>(locations); 

        if (subLocat.Count >= ((i*nSize)+nSize))
            subLocat.RemoveRange(i*nSize, nSize);
        else subLocat.RemoveRange(i*nSize, subLocat.Count-(i*nSize));

        Debug.Log ("Index: "+i.ToString()+", Size: "+subLocat.Count.ToString());
        list.Add (subLocat);
    }

    return list;
}

如果我在144大小的列表上使用该函数,那么输出是:

指数:4,尺寸:120 指数:3,尺寸:114 指数:2,尺寸:114 指数:1,尺寸:114 索引:0,大小:114


当前回答

针对.NET 6的更新

var originalList = new List<int>{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11}

// split into arrays of no more than three
IEnumerable<int[]> chunks = originalList.Chunk(3);

在。net 6之前

public static IEnumerable<IEnumerable<T>> SplitIntoSets<T>
    (this IEnumerable<T> source, int itemsPerSet) 
{
    var sourceList = source as List<T> ?? source.ToList();
    for (var index = 0; index < sourceList.Count; index += itemsPerSet)
    {
        yield return sourceList.Skip(index).Take(itemsPerSet);
    }
}

其他回答

List<int> orginalList =new List<int>(){1,2,3,4,5,6,7,8,9,10,12};
Dictionary<int,List<int>> dic = new Dictionary <int,List<int>> ();
int batchcount = orginalList.Count/2; //To List into two 2 parts if you 
 want three give three
List<int> lst = new List<int>();
for (int i=0;i<orginalList.Count; i++)
{
lst.Add(orginalList[i]);
if (i % batchCount == 0 && i!=0)
{
Dic.Add(threadId, lst);
lst = new List<int>();**strong text**
threadId++;
}
}
if(lst.Count>0)
Dic.Add(threadId, lst); //in case if any dayleft 
foreach(int BatchId in Dic.Keys)
{
  Console.Writeline("BatchId:"+BatchId);
  Console.Writeline('Batch Count:"+Dic[BatchId].Count);
}
public static List<List<T>> ChunkBy<T>(this List<T> source, int chunkSize)
    {           
        var result = new List<List<T>>();
        for (int i = 0; i < source.Count; i += chunkSize)
        {
            var rows = new List<T>();
            for (int j = i; j < i + chunkSize; j++)
            {
                if (j >= source.Count) break;
                rows.Add(source[j]);
            }
            result.Add(rows);
        }
        return result;
    }

多一个

public static IList<IList<T>> SplitList<T>(this IList<T> list, int chunkSize)
{
    var chunks = new List<IList<T>>();
    List<T> chunk = null;
    for (var i = 0; i < list.Count; i++)
    {
        if (i % chunkSize == 0)
        {
            chunk = new List<T>(chunkSize);
            chunks.Add(chunk);
        }
        chunk.Add(list[i]);
    }
    return chunks;
}

在。net 6中,你可以使用source.Chunk(chunkSize)

一个基于Serj-Tm的公认答案的更通用的版本。

    public static IEnumerable<IEnumerable<T>> Split<T>(IEnumerable<T> source, int size = 30)
    {
        var count = source.Count();
        for (int i = 0; i < count; i += size)
        {
            yield return source
                .Skip(Math.Min(size, count - i))
                .Take(size);
        }
    }

我有一个通用的方法,将采取任何类型包括浮动,它已经过单元测试,希望它有帮助:

    /// <summary>
    /// Breaks the list into groups with each group containing no more than the specified group size
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="values">The values.</param>
    /// <param name="groupSize">Size of the group.</param>
    /// <returns></returns>
    public static List<List<T>> SplitList<T>(IEnumerable<T> values, int groupSize, int? maxCount = null)
    {
        List<List<T>> result = new List<List<T>>();
        // Quick and special scenario
        if (values.Count() <= groupSize)
        {
            result.Add(values.ToList());
        }
        else
        {
            List<T> valueList = values.ToList();
            int startIndex = 0;
            int count = valueList.Count;
            int elementCount = 0;

            while (startIndex < count && (!maxCount.HasValue || (maxCount.HasValue && startIndex < maxCount)))
            {
                elementCount = (startIndex + groupSize > count) ? count - startIndex : groupSize;
                result.Add(valueList.GetRange(startIndex, elementCount));
                startIndex += elementCount;
            }
        }


        return result;
    }