在C＃中对List 进行排序
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"
是否有任何想法使用LINQ或Lambda表达式？
提前致谢
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); });
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。
基本上比较算法将识别字符串内的数字，并通过用"Test123Abc"零填充最短的数字来处理它们，因此例如应该比较两个字符串"Test123Abc"和"Test7X"就像它们是"Test123Abc"和"Test007X" ，这应该产生你想要的。
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
- 由于它实际上不会将数字解析为“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 input = new List { "1", "5", "3", "6", "11", "9", "A1", "A0" }; var output = input.NaturalSort(); output.Dump(); } public static class Extensions { public static IEnumerable NaturalSort( this IEnumerable collection) { return NaturalSort(collection, CultureInfo.CurrentCulture); } public static IEnumerable NaturalSort( this IEnumerable collection, CultureInfo cultureInfo) { return collection.OrderBy(s => s, new NaturalComparer(cultureInfo)); } private class NaturalComparer : IComparer { 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; } } }
尝试编写一个小助手类来解析和表示你的令牌。 例如，没有太多检查：
public class NameAndNumber { public NameAndNumber(string s) { OriginalString = s; Match match = Regex.Match(s,@"^(.*?)(\d*)$"); Name = match.Groups[1].Value; int number; int.TryParse(match.Groups[2].Value, out number); Number = number; //will get default value when blank } public string OriginalString { get; private set; } public string Name { get; private set; } public int Number { get; private set; } }
现在编写比较器或手动排序变得容易：
var list = new List { "ABC", "1", "5", "NUM44", "3", "6", "11", "9", "NUM1", "NUM0" }; var sorted = list.Select(str => new NameAndNumber(str)) .OrderBy(n => n.Name) .ThenBy(n => n.Number);
给出结果：
1,3,5,6,9,11，ABC，NUM0，NUM1，NUM44
Jeff Atwood有一篇关于自然排序的博客文章 ，他链接到所需算法的一些可用实现。
Jeffs的一个链接指向Dave Koelle如何实现C＃ ：
/* * The Alphanum Algorithm is an improved sorting algorithm for strings * containing numbers. Instead of sorting numbers in ASCII order like * a standard sort, this algorithm sorts numbers in numeric order. * * The Alphanum Algorithm is discussed at http://www.DaveKoelle.com * * Based on the Java implementation of Dave Koelle's Alphanum algorithm. * Contributed by Jonathan Ruckwood * * Adapted by Dominik Hurnaus to * - correctly sort words where one word starts with another word * - have slightly better performance * * Released under the MIT License - https://opensource.org/licenses/MIT * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE * USE OR OTHER DEALINGS IN THE SOFTWARE. * */ using System; using System.Collections; using System.Text; /* * Please compare against the latest Java version at http://www.DaveKoelle.com * to see the most recent modifications */ namespace AlphanumComparator { public class AlphanumComparator : IComparer { private enum ChunkType {Alphanumeric, Numeric}; private bool InChunk(char ch, char otherCh) { ChunkType type = ChunkType.Alphanumeric; if (char.IsDigit(otherCh)) { type = ChunkType.Numeric; } if ((type == ChunkType.Alphanumeric && char.IsDigit(ch)) || (type == ChunkType.Numeric && !char.IsDigit(ch))) { return false; } return true; } public int Compare(object x, object y) { String s1 = x as string; String s2 = y as string; if (s1 == null || s2 == null) { return 0; } int thisMarker = 0, thisNumericChunk = 0; int thatMarker = 0, thatNumericChunk = 0; while ((thisMarker < s1.Length) || (thatMarker < s2.Length)) { if (thisMarker >= s1.Length) { return -1; } else if (thatMarker >= s2.Length) { return 1; } char thisCh = s1[thisMarker]; char thatCh = s2[thatMarker]; StringBuilder thisChunk = new StringBuilder(); StringBuilder thatChunk = new StringBuilder(); while ((thisMarker < s1.Length) && (thisChunk.Length==0 ||InChunk(thisCh, thisChunk[0]))) { thisChunk.Append(thisCh); thisMarker++; if (thisMarker < s1.Length) { thisCh = s1[thisMarker]; } } while ((thatMarker < s2.Length) && (thatChunk.Length==0 ||InChunk(thatCh, thatChunk[0]))) { thatChunk.Append(thatCh); thatMarker++; if (thatMarker < s2.Length) { thatCh = s2[thatMarker]; } } int result = 0; // If both chunks contain numeric characters, sort them numerically if (char.IsDigit(thisChunk[0]) && char.IsDigit(thatChunk[0])) { thisNumericChunk = Convert.ToInt32(thisChunk.ToString()); thatNumericChunk = Convert.ToInt32(thatChunk.ToString()); if (thisNumericChunk < thatNumericChunk) { result = -1; } if (thisNumericChunk > thatNumericChunk) { result = 1; } } else { result = thisChunk.ToString().CompareTo(thatChunk.ToString()); } if (result != 0) { return result; } } return 0; } } }
这是最快的算法 – 带我2米来分类50项〜
static void Sort() { string[] partNumbers = new string[] {"A1", "A2", "A10", "A111"}; string[] result = partNumbers.OrderBy(x => PadNumbers(x)).ToArray(); } public static string PadNumbers(string input) { const int MAX_NUMBER_LEN = 10; string newInput = ""; string currentNumber = ""; foreach (char a in input) { if (!char.IsNumber(a)) { if (currentNumber == "") { newInput += a; continue; } newInput += "0000000000000".Substring(0, MAX_NUMBER_LEN - currentNumber.Length) + currentNumber; currentNumber = ""; } currentNumber += a; } if (currentNumber != "") { newInput += "0000000000000".Substring(0, MAX_NUMBER_LEN - currentNumber.Length) + currentNumber; } return newInput; }
〜
我认为除了listName.Sort（）之外你不需要任何东西，因为sort（）方法使用默认比较器来快速排序节点。 默认比较器完全符合您的兴趣。
这是一个C＃7解决方案（假设列表的名称为a）：
var numericList = a.Where(i => int.TryParse(i, out _)).OrderBy(j => int.Parse(j)).ToList(); var nonNumericList = a.Where(i => !int.TryParse(i, out _)).OrderBy(j => j).ToList(); a.Clear(); a.AddRange(numericList); a.AddRange(nonNumericList);