c# - 如何将文本转换为 Pascal 大小写？

Question

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

我怎样才能进行这种转换？

score 59 · Accepted Answer

您不需要正则表达式。

var yourString = "WARD_VS_VITAL_SIGNS".ToLower().Replace("_", " ");
TextInfo info = CultureInfo.CurrentCulture.TextInfo;
yourString = info.ToTitleCase(yourString).Replace(" ", string.Empty);
Console.WriteLine(yourString);

score 37 · Accepted Answer

这是我的快速LINQ 和正则表达式解决方案，可以节省别人的时间：

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"

score 22 · Accepted Answer

首先，您要的是标题大小写而不是驼峰大小写，因为在驼峰大小写中，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.

如果您确实想要驼峰式大小写，那么在完成上述所有操作后，只需使用此辅助函数：

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);

score 9 · Accepted Answer

单分号解决方案：

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()));
}

score 7 · Accepted Answer

通过使用和System.String.NET Core 兼容代码的扩展方法。SystemSystem.Linq

不修改原始字符串。

.NET Fiddle 下面的代码

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
    }
}

score 2 · Accepted Answer

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;

score 2 · Accepted Answer

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它将自动处理：

var text = "WARD_VS_VITAL_SIGNS".Replace("_", " ");

TextInfo textInfo = CultureInfo.CurrentCulture.TextInfo;
text = textInfo.ToTitleCase(text).Replace(" ", string.Empty);

Console.WriteLine(text);

score 2 · Accepted Answer

你可以使用这个：

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();
    }

score 1 · Accepted Answer

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（类别）然后是{Pc}标点符号和连接器类型字符的类型；\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，我们得到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为小写，然后仅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

请参阅正则表达式中字符类中的单词字符

PC 标点符号，连接器。这一类包括十个字符，其中最常用的是LOWLINE字符（_），u+005F。

score 0 · Accepted Answer

添加 a 后，我发现这个要点很有用ToLower()。

"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)

c# - 如何将文本转换为 Pascal 大小写？

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