在C#中对List <String>进行排序

Question

如何根据项的整数值对List进行排序

清单就像

"1"
"5"
"3"
"6"
"11"
"9"
"NUM1"
"NUM0"

结果应该是这样的

"1"
"3"
"5"
"6"
"9"
"11"
"NUM0"
"NUM1"

有什么想法使用LINQ或Lambda表达式吗？

提前致谢

Answer 1

怎么样:

    list.Sort((x, y) =>
    {
        int ix, iy;
        return int.TryParse(x, out ix) && int.TryParse(y, out iy)
              ? ix.CompareTo(iy) : string.Compare(x, y);
    });

Answer 2

这被称为"自然排序顺序",通常用于对您拥有的项目进行排序,如文件名等.

这是一个天真的(在某种意义上,它可能存在大量的unicode问题)实现似乎可以解决这个问题:

您可以将以下代码复制到LINQPad中以执行它并进行测试.

基本上比较算法将确定数字字符串内,并通过填充最短的一个具有前导零处理这些,所以比如两个字符串"Test123Abc",并"Test7X"应就好像它们是进行比较"Test123Abc"和"Test007X",这应该产生你想要什么.

然而,当我说"天真"时,我的意思是我可能在这里有很多真正的unicode问题,比如处理变音符号和多码点字符.如果有人能够提供更好的实施,我很乐意看到它.

笔记:

• 实现实际上并没有解析数字,所以任意长数应该可以正常工作
• 由于它实际上并没有将数字解析为"数字",因此浮点数将无法正确处理,"123.45"与"123.789"将被比较为"123.045"与"123.789",这是错误的.

码:

void Main()
{
    List<string> input = new List<string>
    {
        "1", "5", "3", "6", "11", "9", "A1", "A0"
    };
    var output = input.NaturalSort();
    output.Dump();
}

public static class Extensions
{
    public static IEnumerable<string> NaturalSort(
        this IEnumerable<string> collection)
    {
        return NaturalSort(collection, CultureInfo.CurrentCulture);
    }

    public static IEnumerable<string> NaturalSort(
        this IEnumerable<string> collection, CultureInfo cultureInfo)
    {
        return collection.OrderBy(s => s, new NaturalComparer(cultureInfo));
    }

    private class NaturalComparer : IComparer<string>
    {
        private readonly CultureInfo _CultureInfo;

        public NaturalComparer(CultureInfo cultureInfo)
        {
            _CultureInfo = cultureInfo;
        }

        public int Compare(string x, string y)
        {
            // simple cases
            if (x == y) // also handles null
                return 0;
            if (x == null)
                return -1;
            if (y == null)
                return +1;

            int ix = 0;
            int iy = 0;
            while (ix < x.Length && iy < y.Length)
            {
                if (Char.IsDigit(x[ix]) && Char.IsDigit(y[iy]))
                {
                    // We found numbers, so grab both numbers
                    int ix1 = ix++;
                    int iy1 = iy++;
                    while (ix < x.Length && Char.IsDigit(x[ix]))
                        ix++;
                    while (iy < y.Length && Char.IsDigit(y[iy]))
                        iy++;
                    string numberFromX = x.Substring(ix1, ix - ix1);
                    string numberFromY = y.Substring(iy1, iy - iy1);

                    // Pad them with 0's to have the same length
                    int maxLength = Math.Max(
                        numberFromX.Length,
                        numberFromY.Length);
                    numberFromX = numberFromX.PadLeft(maxLength, '0');
                    numberFromY = numberFromY.PadLeft(maxLength, '0');

                    int comparison = _CultureInfo
                        .CompareInfo.Compare(numberFromX, numberFromY);
                    if (comparison != 0)
                        return comparison;
                }
                else
                {
                    int comparison = _CultureInfo
                        .CompareInfo.Compare(x, ix, 1, y, iy, 1);
                    if (comparison != 0)
                        return comparison;
                    ix++;
                    iy++;
                }
            }

            // we should not be here with no parts left, they're equal
            Debug.Assert(ix < x.Length || iy < y.Length);

            // we still got parts of x left, y comes first
            if (ix < x.Length)
                return +1;

            // we still got parts of y left, x comes first
            return -1;
        }
    }
}