C# 将字符串大写，但仅在某些标点符号之后

Question

我试图找到一种有效的方法来获取输入字符串并将每个标点符号（. : ? !）后的第一个字母大写，后面跟着一个空格。

输入：

“我吃了一些东西，但我没有： 相反，不。你怎么认为？我 不认为！对不起，我”

输出：

“我吃了东西。但我没有： 相反，不。你怎么认为？我 不认为！对不起.moi”

显而易见的是，将其拆分，然后将每个组的第一个字符大写，然后连接所有内容。但这非常丑陋。执行此操作的最佳方法是什么？（我在想 Regex.Replace 使用 MatchEvaluator 将第一个字母大写，但希望获得更多想法）

谢谢！

Answer 1

快速简单：

static class Ext
{
    public static string CapitalizeAfter(this string s, IEnumerable<char> chars)
    {
        var charsHash = new HashSet<char>(chars);
        StringBuilder sb = new StringBuilder(s);
        for (int i = 0; i < sb.Length - 2; i++)
        {
            if (charsHash.Contains(sb[i]) && sb[i + 1] == ' ')
                sb[i + 2] = char.ToUpper(sb[i + 2]);
        }
        return sb.ToString();
    }
}

用法：

string capitalized = s.CapitalizeAfter(new[] { '.', ':', '?', '!' });

Answer 2

试试这个：

string expression = @"[\.\?\!,]\s+([a-z])";
string input = "I ate something. but I didn't: instead, no. what do you think? i think not! excuse me.moi";
char[] charArray = input.ToCharArray();
foreach (Match match in Regex.Matches(input, expression,RegexOptions.Singleline))
{
    charArray[match.Groups[1].Index] = Char.ToUpper(charArray[match.Groups[1].Index]);
}
string output = new string(charArray);
// "I ate something. But I didn't: instead, No. What do you think? I think not! Excuse me.moi"

Answer 3

我使用扩展方法。

public static string CorrectTextCasing(this string text)
{
    //  /[.:?!]\\s[a-z]/ matches letters following a space and punctuation,
    //  /^(?:\\s+)?[a-z]/  matches the first letter in a string (with optional leading spaces)
    Regex regexCasing = new Regex("(?:[.:?!]\\s[a-z]|^(?:\\s+)?[a-z])", RegexOptions.Multiline);

    //  First ensure all characters are lower case.  
    //  (In my case it comes all in caps; this line may be omitted depending upon your needs)        
    text = text.ToLower();

    //  Capitalize each match in the regular expression, using a lambda expression
    text = regexCasing.Replace(text, s => (s.Value.ToUpper));

    //  Return the new string.
    return text;

}

然后我可以执行以下操作：

string mangled = "i'm A little teapot, short AND stout. here IS my Handle.";
string corrected = s.CorrectTextCasing();
//  returns "I'm a little teapot, short and stout.  Here is my handle."

Answer 4

使用 Regex / MatchEvaluator 路由，您可以匹配

"[.:?!]\s[a-z]"

整个匹配并将其大写。

Answer 5

其中文本变量包含字符串

        string text = "I ate something. but I didn't: instead, no. what do you think? i think not! excuse me.moi";
        string[] punctuators = { "?", "!", ",", "-", ":", ";", "." };
        for (int i = 0; i< 7;i++)
        {
            int pos = text.IndexOf(punctuators[i]);
            while(pos!=-1)
            {
                text = text.Insert(pos+2, char.ToUpper(text[pos + 2]).ToString());
                text = text.Remove(pos + 3, 1);
                pos = text.IndexOf(punctuators[i],pos+1);
            }
        }