é
转换为 e
,因此 crème brûlée
将变为 creme brulee
)最好的方法是什么?é
转换为 e
,因此 crème brûlée
将变为 creme brulee
)最好的方法是什么?我没有使用过这种方法,但是迈克尔·卡普兰在他的博客文章中描述了一种方法来实现这一点(标题有些令人困惑),该文章讨论了去除变音符号:去除是一项有趣的工作(又名关于无意义的意义,或者所有Mn字符都是非间距的,但有些比其他的更非间距)
static string RemoveDiacritics(string text)
{
var normalizedString = text.Normalize(NormalizationForm.FormD);
var stringBuilder = new StringBuilder(capacity: normalizedString.Length);
for (int i = 0; i < normalizedString.Length; i++)
{
char c = normalizedString[i];
var unicodeCategory = CharUnicodeInfo.GetUnicodeCategory(c);
if (unicodeCategory != UnicodeCategory.NonSpacingMark)
{
stringBuilder.Append(c);
}
}
return stringBuilder
.ToString()
.Normalize(NormalizationForm.FormC);
}
请注意,这是他早期帖子的后续内容:Stripping diacritics....
该方法使用String.Normalize将输入字符串拆分为组成字符(从根本上分离“基”字符与附加符号),然后扫描结果并仅保留基字符。 原理有点复杂,但确实是一个复杂的问题。
当然,如果您只限于法语,则可以使用简单的基于表格的方法,如@David Dibben建议的How to remove accents and tilde in a C++ std::string。
这对我起了作用...
string accentedStr;
byte[] tempBytes;
tempBytes = System.Text.Encoding.GetEncoding("ISO-8859-8").GetBytes(accentedStr);
string asciiStr = System.Text.Encoding.UTF8.GetString(tempBytes);
快速&简短!
«
»
和 …
(作为单个字符),在此过程中将被改变,而这不是被接受的解决方案所能解决的。 - The_Black_SmurfSystem.ArgumentException: 'ISO-8859-8' 不是受支持的编码名称。
- EM0System.Text.Encoding.CodePages
, 然后调用以下代码注册编码提供程序:Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
。一旦完成这些步骤,就可以使用ISO-8859-8编码。请注意,不要改变原文的意思。 - SpaceBison我需要一个能转换所有主要Unicode字符的东西,但是所选答案有一些遗漏,因此我创建了一个易于定制的CodeIgniter的convert_accented_characters($str)
版本,它可以用于C#:
using System;
using System.Text;
using System.Collections.Generic;
public static class Strings
{
static Dictionary<string, string> foreign_characters = new Dictionary<string, string>
{
{ "äæǽ", "ae" },
{ "öœ", "oe" },
{ "ü", "ue" },
{ "Ä", "Ae" },
{ "Ü", "Ue" },
{ "Ö", "Oe" },
{ "ÀÁÂÃÄÅǺĀĂĄǍΑΆẢẠẦẪẨẬẰẮẴẲẶА", "A" },
{ "àáâãåǻāăąǎªαάảạầấẫẩậằắẵẳặа", "a" },
{ "Б", "B" },
{ "б", "b" },
{ "ÇĆĈĊČ", "C" },
{ "çćĉċč", "c" },
{ "Д", "D" },
{ "д", "d" },
{ "ÐĎĐΔ", "Dj" },
{ "ðďđδ", "dj" },
{ "ÈÉÊËĒĔĖĘĚΕΈẼẺẸỀẾỄỂỆЕЭ", "E" },
{ "èéêëēĕėęěέεẽẻẹềếễểệеэ", "e" },
{ "Ф", "F" },
{ "ф", "f" },
{ "ĜĞĠĢΓГҐ", "G" },
{ "ĝğġģγгґ", "g" },
{ "ĤĦ", "H" },
{ "ĥħ", "h" },
{ "ÌÍÎÏĨĪĬǏĮİΗΉΊΙΪỈỊИЫ", "I" },
{ "ìíîïĩīĭǐįıηήίιϊỉịиыї", "i" },
{ "Ĵ", "J" },
{ "ĵ", "j" },
{ "ĶΚК", "K" },
{ "ķκк", "k" },
{ "ĹĻĽĿŁΛЛ", "L" },
{ "ĺļľŀłλл", "l" },
{ "М", "M" },
{ "м", "m" },
{ "ÑŃŅŇΝН", "N" },
{ "ñńņňʼnνн", "n" },
{ "ÒÓÔÕŌŎǑŐƠØǾΟΌΩΏỎỌỒỐỖỔỘỜỚỠỞỢО", "O" },
{ "òóôõōŏǒőơøǿºοόωώỏọồốỗổộờớỡởợо", "o" },
{ "П", "P" },
{ "п", "p" },
{ "ŔŖŘΡР", "R" },
{ "ŕŗřρр", "r" },
{ "ŚŜŞȘŠΣС", "S" },
{ "śŝşșšſσςс", "s" },
{ "ȚŢŤŦτТ", "T" },
{ "țţťŧт", "t" },
{ "ÙÚÛŨŪŬŮŰŲƯǓǕǗǙǛŨỦỤỪỨỮỬỰУ", "U" },
{ "ùúûũūŭůűųưǔǖǘǚǜυύϋủụừứữửựу", "u" },
{ "ÝŸŶΥΎΫỲỸỶỴЙ", "Y" },
{ "ýÿŷỳỹỷỵй", "y" },
{ "В", "V" },
{ "в", "v" },
{ "Ŵ", "W" },
{ "ŵ", "w" },
{ "ŹŻŽΖЗ", "Z" },
{ "źżžζз", "z" },
{ "ÆǼ", "AE" },
{ "ß", "ss" },
{ "IJ", "IJ" },
{ "ij", "ij" },
{ "Œ", "OE" },
{ "ƒ", "f" },
{ "ξ", "ks" },
{ "π", "p" },
{ "β", "v" },
{ "μ", "m" },
{ "ψ", "ps" },
{ "Ё", "Yo" },
{ "ё", "yo" },
{ "Є", "Ye" },
{ "є", "ye" },
{ "Ї", "Yi" },
{ "Ж", "Zh" },
{ "ж", "zh" },
{ "Х", "Kh" },
{ "х", "kh" },
{ "Ц", "Ts" },
{ "ц", "ts" },
{ "Ч", "Ch" },
{ "ч", "ch" },
{ "Ш", "Sh" },
{ "ш", "sh" },
{ "Щ", "Shch" },
{ "щ", "shch" },
{ "ЪъЬь", "" },
{ "Ю", "Yu" },
{ "ю", "yu" },
{ "Я", "Ya" },
{ "я", "ya" },
};
public static char RemoveDiacritics(this char c){
foreach(KeyValuePair<string, string> entry in foreign_characters)
{
if(entry.Key.IndexOf (c) != -1)
{
return entry.Value[0];
}
}
return c;
}
public static string RemoveDiacritics(this string s)
{
//StringBuilder sb = new StringBuilder ();
string text = "";
foreach (char c in s)
{
int len = text.Length;
foreach(KeyValuePair<string, string> entry in foreign_characters)
{
if(entry.Key.IndexOf (c) != -1)
{
text += entry.Value;
break;
}
}
if (len == text.Length) {
text += c;
}
}
return text;
}
}
使用方法
// for strings
"crème brûlée".RemoveDiacritics (); // creme brulee
// for chars
"Ã"[0].RemoveDiacritics (); // A
{"äæǽ","ae"}
而不是{"ä","ae"}
、{"æ","ae"}
和{"ǽ","ae"}
,然后调用if (foreign_characters.TryGetValue(...)) ...
。你已经完全打败了字典已经具有的索引的目的。 - Bacon BitsCharUnicodeInfo
,因为C#&.NET在最新版本中更新了分析字符串的方式(Rune类已添加到.NET Core 3.0)。static string RemoveDiacritics(string text)
{
var normalizedString = text.Normalize(NormalizationForm.FormD);
var stringBuilder = new StringBuilder();
foreach (var c in normalizedString.EnumerateRunes())
{
var unicodeCategory = Rune.GetUnicodeCategory(c);
if (unicodeCategory != UnicodeCategory.NonSpacingMark)
{
stringBuilder.Append(c);
}
}
return stringBuilder.ToString().Normalize(NormalizationForm.FormC);
}
如果有人感兴趣,我在寻找类似的东西时最终写出了以下内容:
public static string NormalizeStringForUrl(string name)
{
String normalizedString = name.Normalize(NormalizationForm.FormD);
StringBuilder stringBuilder = new StringBuilder();
foreach (char c in normalizedString)
{
switch (CharUnicodeInfo.GetUnicodeCategory(c))
{
case UnicodeCategory.LowercaseLetter:
case UnicodeCategory.UppercaseLetter:
case UnicodeCategory.DecimalDigitNumber:
stringBuilder.Append(c);
break;
case UnicodeCategory.SpaceSeparator:
case UnicodeCategory.ConnectorPunctuation:
case UnicodeCategory.DashPunctuation:
stringBuilder.Append('_');
break;
}
}
string result = stringBuilder.ToString();
return String.Join("_", result.Split(new char[] { '_' }
, StringSplitOptions.RemoveEmptyEntries)); // remove duplicate underscores
}
我经常使用一个基于找到的另一个版本的扩展方法(见Replacing characters in C# (ascii))
代码:
using System.Linq;
using System.Text;
using System.Globalization;
// namespace here
public static class Utility
{
public static string RemoveDiacritics(this string str)
{
if (null == str) return null;
var chars =
from c in str.Normalize(NormalizationForm.FormD).ToCharArray()
let uc = CharUnicodeInfo.GetUnicodeCategory(c)
where uc != UnicodeCategory.NonSpacingMark
select c;
var cleanStr = new string(chars.ToArray()).Normalize(NormalizationForm.FormC);
return cleanStr;
}
// or, alternatively
public static string RemoveDiacritics2(this string str)
{
if (null == str) return null;
var chars = str
.Normalize(NormalizationForm.FormD)
.ToCharArray()
.Where(c=> CharUnicodeInfo.GetUnicodeCategory(c) != UnicodeCategory.NonSpacingMark)
.ToArray();
return new string(chars).Normalize(NormalizationForm.FormC);
}
}
希腊编码(ISO)可以做到这一点
有关此代码页的信息位于System.Text.Encoding.GetEncodings()
。请参阅:https://msdn.microsoft.com/pt-br/library/system.text.encodinginfo.getencoding(v=vs.110).aspx
Greek (ISO) 编码为 28597,名称为 iso-8859-7。
前往代码... \o/
string text = "Você está numa situação lamentável";
string textEncode = System.Web.HttpUtility.UrlEncode(text, Encoding.GetEncoding("iso-8859-7"));
//result: "Voce+esta+numa+situacao+lamentavel"
string textDecode = System.Web.HttpUtility.UrlDecode(textEncode);
//result: "Voce esta numa situacao lamentavel"
因此,编写这个函数...
public string RemoveAcentuation(string text)
{
return
System.Web.HttpUtility.UrlDecode(
System.Web.HttpUtility.UrlEncode(
text, Encoding.GetEncoding("iso-8859-7")));
}
请注意,Encoding.GetEncoding("iso-8859-7")
等同于 Encoding.GetEncoding(28597)
,因为前者是名称,后者是编码页的表示。äáčďěéíľľňôóřŕšťúůýž ÄÁČĎĚÉÍĽĽŇÔÓŘŔŠŤÚŮÝŽ ÖÜË łŁđĐ ţŢşŞçÇ øı
)。只有 ßə
出现了问题,被转换成了 ?
,但这样的例外总是可以单独处理的。在投入生产之前,最好对所有包含带变音符号字母的 Unicode 区域进行更好的测试。 - miroxlavTL;DR - C#字符串扩展方法
我认为保留字符串的含义的最佳解决方案是转换字符而不是剥离它们,这在例子crème brûlée
tocrme brle
与creme brulee
中得到了很好的说明。
我查看了上面亚历山大的评论,发现 Lucene.Net 代码是 Apache 2.0 授权的,因此我将该类修改为一个简单的字符串扩展方法。你可以像这样使用它:
var originalString = "crème brûlée";
var maxLength = originalString.Length; // limit output length as necessary
var foldedString = originalString.FoldToASCII(maxLength);
// "creme brulee"
这个函数太长了,无法在StackOverflow的回答中发布(30k允许的字符数只有 ~139k),所以我制作了一个代码片段,并注明了作者:
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/// <summary>
/// This class converts alphabetic, numeric, and symbolic Unicode characters
/// which are not in the first 127 ASCII characters (the "Basic Latin" Unicode
/// block) into their ASCII equivalents, if one exists.
/// <para/>
/// Characters from the following Unicode blocks are converted; however, only
/// those characters with reasonable ASCII alternatives are converted:
///
/// <ul>
/// <item><description>C1 Controls and Latin-1 Supplement: <a href="http://www.unicode.org/charts/PDF/U0080.pdf">http://www.unicode.org/charts/PDF/U0080.pdf</a></description></item>
/// <item><description>Latin Extended-A: <a href="http://www.unicode.org/charts/PDF/U0100.pdf">http://www.unicode.org/charts/PDF/U0100.pdf</a></description></item>
/// <item><description>Latin Extended-B: <a href="http://www.unicode.org/charts/PDF/U0180.pdf">http://www.unicode.org/charts/PDF/U0180.pdf</a></description></item>
/// <item><description>Latin Extended Additional: <a href="http://www.unicode.org/charts/PDF/U1E00.pdf">http://www.unicode.org/charts/PDF/U1E00.pdf</a></description></item>
/// <item><description>Latin Extended-C: <a href="http://www.unicode.org/charts/PDF/U2C60.pdf">http://www.unicode.org/charts/PDF/U2C60.pdf</a></description></item>
/// <item><description>Latin Extended-D: <a href="http://www.unicode.org/charts/PDF/UA720.pdf">http://www.unicode.org/charts/PDF/UA720.pdf</a></description></item>
/// <item><description>IPA Extensions: <a href="http://www.unicode.org/charts/PDF/U0250.pdf">http://www.unicode.org/charts/PDF/U0250.pdf</a></description></item>
/// <item><description>Phonetic Extensions: <a href="http://www.unicode.org/charts/PDF/U1D00.pdf">http://www.unicode.org/charts/PDF/U1D00.pdf</a></description></item>
/// <item><description>Phonetic Extensions Supplement: <a href="http://www.unicode.org/charts/PDF/U1D80.pdf">http://www.unicode.org/charts/PDF/U1D80.pdf</a></description></item>
/// <item><description>General Punctuation: <a href="http://www.unicode.org/charts/PDF/U2000.pdf">http://www.unicode.org/charts/PDF/U2000.pdf</a></description></item>
/// <item><description>Superscripts and Subscripts: <a href="http://www.unicode.org/charts/PDF/U2070.pdf">http://www.unicode.org/charts/PDF/U2070.pdf</a></description></item>
/// <item><description>Enclosed Alphanumerics: <a href="http://www.unicode.org/charts/PDF/U2460.pdf">http://www.unicode.org/charts/PDF/U2460.pdf</a></description></item>
/// <item><description>Dingbats: <a href="http://www.unicode.org/charts/PDF/U2700.pdf">http://www.unicode.org/charts/PDF/U2700.pdf</a></description></item>
/// <item><description>Supplemental Punctuation: <a href="http://www.unicode.org/charts/PDF/U2E00.pdf">http://www.unicode.org/charts/PDF/U2E00.pdf</a></description></item>
/// <item><description>Alphabetic Presentation Forms: <a href="http://www.unicode.org/charts/PDF/UFB00.pdf">http://www.unicode.org/charts/PDF/UFB00.pdf</a></description></item>
/// <item><description>Halfwidth and Fullwidth Forms: <a href="http://www.unicode.org/charts/PDF/UFF00.pdf">http://www.unicode.org/charts/PDF/UFF00.pdf</a></description></item>
/// </ul>
/// <para/>
/// See: <a href="http://en.wikipedia.org/wiki/Latin_characters_in_Unicode">http://en.wikipedia.org/wiki/Latin_characters_in_Unicode</a>
/// <para/>
/// For example, '&agrave;' will be replaced by 'a'.
/// </summary>
public static partial class StringExtensions
{
/// <summary>
/// Converts characters above ASCII to their ASCII equivalents. For example,
/// accents are removed from accented characters.
/// </summary>
/// <param name="input"> The string of characters to fold </param>
/// <param name="length"> The length of the folded return string </param>
/// <returns> length of output </returns>
public static string FoldToASCII(this string input, int? length = null)
{
// See https://gist.github.com/andyraddatz/e6a396fb91856174d4e3f1bf2e10951c
}
}
希望这能对其他人有所帮助,这是我找到的最稳定的解决方案!
}
括号。 - Superman.LopezSpan
而不是 StringBuilder
。
需要 .NET Core 3.1 或更新版本的.NET。static string RemoveDiacritics(string text)
{
ReadOnlySpan<char> normalizedString = text.Normalize(NormalizationForm.FormD);
int i = 0;
Span<char> span = text.Length < 1000
? stackalloc char[text.Length]
: new char[text.Length];
foreach (char c in normalizedString)
{
if (CharUnicodeInfo.GetUnicodeCategory(c) != UnicodeCategory.NonSpacingMark)
span[i++] = c;
}
return new string(span).Normalize(NormalizationForm.FormC);
}
此外,它还可以扩展以进行其他字符替换,例如波兰字母Ł。
span[i++] = c switch
{
'Ł' => 'L',
'ł' => 'l',
_ => c
};
一个小提示:栈分配stackalloc
比堆分配new
更快,并且对垃圾回收器的工作量更小。 1000
是为避免在堆栈上分配大型结构(可能导致StackOverflowException
)而设置的阈值。虽然1000是非常安全的值,在大多数情况下,10000甚至100000也可以使用(100k在堆栈上分配高达200kB,而默认堆栈大小为1 MB)。不过,对我来说,100k看起来有点危险。
有趣的是,这样一个问题可以得到如此多的答案,但是没有一个符合我的要求 :) 有那么多的语言存在,完全面向语言不可行,因为其他人提到了FormC或FormD会出现问题。
由于原来的问题与法语有关,最简单的有效答案确实是
public static string ConvertWesternEuropeanToASCII(this string str)
{
return Encoding.ASCII.GetString(Encoding.GetEncoding(1251).GetBytes(str));
}
1251 应该被替换成输入语言的编码。
但是这样只能逐个字符地进行替换。因为我也在处理德语输入,所以我手动进行了转换。
public static string LatinizeGermanCharacters(this string str)
{
StringBuilder sb = new StringBuilder(str.Length);
foreach (char c in str)
{
switch (c)
{
case 'ä':
sb.Append("ae");
break;
case 'ö':
sb.Append("oe");
break;
case 'ü':
sb.Append("ue");
break;
case 'Ä':
sb.Append("Ae");
break;
case 'Ö':
sb.Append("Oe");
break;
case 'Ü':
sb.Append("Ue");
break;
case 'ß':
sb.Append("ss");
break;
default:
sb.Append(c);
break;
}
}
return sb.ToString();
}
public static string RemoveSpace(this string str)
{
return str.Replace(" ", string.Empty);
}
public static string LatinizeAndConvertToASCII(this string str, bool keepSpace = false)
{
str = str.LatinizeGermanCharacters().ConvertWesternEuropeanToASCII();
return keepSpace ? str : str.RemoveSpace();
}
再加上一个小的单元测试(不详尽),该测试已经成功通过。
[TestMethod()]
public void LatinizeAndConvertToASCIITest()
{
string europeanStr = "Bonjour ça va? C'est l'été! Ich möchte ä Ä á à â ê é è ë Ë É ï Ï î í ì ó ò ô ö Ö Ü ü ù ú û Û ý Ý ç Ç ñ Ñ";
string expected = "Bonjourcava?C'estl'ete!IchmoechteaeAeaaaeeeeEEiIiiiooooeOeUeueuuuUyYcCnN";
string actual = europeanStr.LatinizeAndConvertToASCII();
Assert.AreEqual(expected, actual);
}
[a-zA-Z0-9_]
。而对于我们的情况,确实需要进行快速搜索。 - Mike de Klerk