我有一个变量名，比如“WARD_VS_VITAL_SIGNS”，我想将其转换为 Pascal 大小写格式：“WardVsVitalSigns”
WARD_VS_VITAL_SIGNS -> WardVsVitalSigns
如何进行这种转换？
【问题讨论】：
标签： c# pascalcasing case-conversion
你不需要正则表达式。
var yourString = "WARD_VS_VITAL_SIGNS".ToLower().Replace("_", " ");
TextInfo info = CultureInfo.CurrentCulture.TextInfo;
yourString = info.ToTitleCase(yourString).Replace(" ", string.Empty);
Console.WriteLine(yourString);
【讨论】：
这是我的快速 LINQ 和正则表达式解决方案，以节省某人的时间：
using System;
using System.Linq;
using System.Text.RegularExpressions;
public string ToPascalCase(string original)
{
Regex invalidCharsRgx = new Regex("[^_a-zA-Z0-9]");
Regex whiteSpace = new Regex(@"(?<=\s)");
Regex startsWithLowerCaseChar = new Regex("^[a-z]");
Regex firstCharFollowedByUpperCasesOnly = new Regex("(?<=[A-Z])[A-Z0-9]+$");
Regex lowerCaseNextToNumber = new Regex("(?<=[0-9])[a-z]");
Regex upperCaseInside = new Regex("(?<=[A-Z])[A-Z]+?((?=[A-Z][a-z])|(?=[0-9]))");
// replace white spaces with undescore, then replace all invalid chars with empty string
var pascalCase = invalidCharsRgx.Replace(whiteSpace.Replace(original, "_"), string.Empty)
// split by underscores
.Split(new char[] { '_' }, StringSplitOptions.RemoveEmptyEntries)
// set first letter to uppercase
.Select(w => startsWithLowerCaseChar.Replace(w, m => m.Value.ToUpper()))
// replace second and all following upper case letters to lower if there is no next lower (ABC -> Abc)
.Select(w => firstCharFollowedByUpperCasesOnly.Replace(w, m => m.Value.ToLower()))
// set upper case the first lower case following a number (Ab9cd -> Ab9Cd)
.Select(w => lowerCaseNextToNumber.Replace(w, m => m.Value.ToUpper()))
// lower second and next upper case letters except the last if it follows by any lower (ABcDEf -> AbcDef)
.Select(w => upperCaseInside.Replace(w, m => m.Value.ToLower()));
return string.Concat(pascalCase);
}
示例输出：
"WARD_VS_VITAL_SIGNS" "WardVsVitalSigns"
"Who am I?" "WhoAmI"
"I ate before you got here" "IAteBeforeYouGotHere"
"Hello|Who|Am|I?" "HelloWhoAmI"
"Live long and prosper" "LiveLongAndProsper"
"Lorem ipsum dolor..." "LoremIpsumDolor"
"CoolSP" "CoolSp"
"AB9CD" "Ab9Cd"
"CCCTrigger" "CccTrigger"
"CIRC" "Circ"
"ID_SOME" "IdSome"
"ID_SomeOther" "IdSomeOther"
"ID_SOMEOther" "IdSomeOther"
"CCC_SOME_2Phases" "CccSome2Phases"
"AlreadyGoodPascalCase" "AlreadyGoodPascalCase"
"999 999 99 9 " "999999999"
"1 2 3 " "123"
"1 AB cd EFDDD 8" "1AbCdEfddd8"
"INVALID VALUE AND _2THINGS" "InvalidValueAnd2Things"
【讨论】：
首先，您要的是标题大小写而不是驼峰式，因为在驼峰式中，单词的第一个字母是小写的，而您的示例显示您希望第一个字母为大写。
无论如何，您可以通过以下方式实现您想要的结果：
string textToChange = "WARD_VS_VITAL_SIGNS";
System.Text.StringBuilder resultBuilder = new System.Text.StringBuilder();
foreach(char c in textToChange)
{
// Replace anything, but letters and digits, with space
if(!Char.IsLetterOrDigit(c))
{
resultBuilder.Append(" ");
}
else
{
resultBuilder.Append(c);
}
}
string result = resultBuilder.ToString();
// Make result string all lowercase, because ToTitleCase does not change all uppercase correctly
result = result.ToLower();
// Creates a TextInfo based on the "en-US" culture.
TextInfo myTI = new CultureInfo("en-US",false).TextInfo;
result = myTI.ToTitleCase(result).Replace(" ", String.Empty);
注意：result 现在是 WardVsVitalSigns。
如果你确实想要驼峰式，那么在上述所有之后，只需使用这个辅助函数：
public string LowercaseFirst(string s)
{
if (string.IsNullOrEmpty(s))
{
return string.Empty;
}
char[] a = s.ToCharArray();
a[0] = char.ToLower(a[0]);
return new string(a);
}
所以你可以这样称呼它：
result = LowercaseFirst(result);
【讨论】：
if(!Char.IsLetterOrDigit(c)) { resultBuilder.Append(" "); } 应该是if (!Char.IsLetterOrDigit(c)) { resultBuilder.Append(" "); } else { resultBuilder.Append(c); }，否则，resultBuilder 总是为空的。 ;-)
单分号解法：
public static string PascalCase(this string word)
{
return string.Join("" , word.Split('_')
.Select(w => w.Trim())
.Where(w => w.Length > 0)
.Select(w => w.Substring(0,1).ToUpper() + w.Substring(1).ToLower()));
}
【讨论】：
使用System 和System.Linq 与.NET Core 兼容代码的System.String 的扩展方法。
是否不修改原始字符串。
.NET Fiddle for the code below
using System;
using System.Linq;
public static class StringExtensions
{
/// <summary>
/// Converts a string to PascalCase
/// </summary>
/// <param name="str">String to convert</param>
public static string ToPascalCase(this string str){
// Replace all non-letter and non-digits with an underscore and lowercase the rest.
string sample = string.Join("", str?.Select(c => Char.IsLetterOrDigit(c) ? c.ToString().ToLower() : "_").ToArray());
// Split the resulting string by underscore
// Select first character, uppercase it and concatenate with the rest of the string
var arr = sample?
.Split(new []{'_'}, StringSplitOptions.RemoveEmptyEntries)
.Select(s => $"{s.Substring(0, 1).ToUpper()}{s.Substring(1)}");
// Join the resulting collection
sample = string.Join("", arr);
return sample;
}
}
public class Program
{
public static void Main()
{
Console.WriteLine("WARD_VS_VITAL_SIGNS".ToPascalCase()); // WardVsVitalSigns
Console.WriteLine("Who am I?".ToPascalCase()); // WhoAmI
Console.WriteLine("I ate before you got here".ToPascalCase()); // IAteBeforeYouGotHere
Console.WriteLine("Hello|Who|Am|I?".ToPascalCase()); // HelloWhoAmI
Console.WriteLine("Live long and prosper".ToPascalCase()); // LiveLongAndProsper
Console.WriteLine("Lorem ipsum dolor sit amet, consectetur adipiscing elit.".ToPascalCase()); // LoremIpsumDolorSitAmetConsecteturAdipiscingElit
}
}
【讨论】：
var xs = "WARD_VS_VITAL_SIGNS".Split('_');
var q =
from x in xs
let first_char = char.ToUpper(x[0])
let rest_chars = new string(x.Skip(1).Select(c => char.ToLower(c)).ToArray())
select first_char + rest_chars;
【讨论】：
有些答案是正确的，但我真的不明白为什么他们首先将文本设置为小写，因为ToTitleCase 会自动处理：
var text = "WARD_VS_VITAL_SIGNS".Replace("_", " ");
TextInfo textInfo = CultureInfo.CurrentCulture.TextInfo;
text = textInfo.ToTitleCase(text).Replace(" ", string.Empty);
Console.WriteLine(text);
【讨论】：
你可以用这个：
public static string ConvertToPascal(string underScoreString)
{
string[] words = underScoreString.Split('_');
StringBuilder returnStr = new StringBuilder();
foreach (string wrd in words)
{
returnStr.Append(wrd.Substring(0, 1).ToUpper());
returnStr.Append(wrd.Substring(1).ToLower());
}
return returnStr.ToString();
}
【讨论】：
此答案了解在处理文本时可以点击 Unicode 类别以忽略连接字符，例如 - 或 _。在正则表达式中，它是\p（用于类别）然后是{Pc} 用于punctuation 和connector 类型字符的类型； \p{Pc} 使用我们的 MatchEvaluator，它为会话中的每场比赛启动。
所以在匹配阶段，我们获取单词并忽略标点符号，因此替换操作处理连接符的删除。一旦我们有了匹配词，我们可以将其向下推到小写，然后只将第一个字符向上大写作为替换的返回：
public static class StringExtensions
{
public static string ToPascalCase(this string initial)
=> Regex.Replace(initial,
// (Match any non punctuation) & then ignore any punctuation
@"([^\p{Pc}]+)[\p{Pc}]*",
new MatchEvaluator(mtch =>
{
var word = mtch.Groups[1].Value.ToLower();
return $"{Char.ToUpper(word[0])}{word.Substring(1)}";
}));
}
用法：
"TOO_MUCH_BABY".ToPascalCase(); // TooMuchBaby
"HELLO|ITS|ME".ToPascalCase(); // HelloItsMe
见Word Character in Character Classes in Regular Expressions
PC 标点符号，连接器。此类别包括十个字符， 其中最常用的是LOWLINE字符（_），u+005F。
【讨论】：
添加ToLower() 后，我发现this gist 很有用。
"WARD_VS_VITAL_SIGNS".ToLower().Split(new [] {"_"}, StringSplitOptions.RemoveEmptyEntries).Select(s => char.ToUpperInvariant(s[0]) + s.Substring(1, s.Length - 1)).Aggregate(string.Empty, (s1, s2) => s1 + s2)
【讨论】：