我想在两个命名捕获组之间的特定位置插入一个美元符号。问题在于,这意味着替换字符串中的两个美元符号紧随其后,这会导致问题。
我怎样才能直接用 Replace-method 做到这一点?我只是通过添加一些我立即再次删除的临时垃圾找到了解决方法。
问题见代码:
// We want to add a dollar sign before a number and use named groups for capturing;
// varying parts of the strings are in brackets []
// [somebody] has [some-dollar-amount] in his [something]
string joeHas = "Joe has 500 in his wallet.";
string jackHas = "Jack has 500 in his pocket.";
string jimHas = "Jim has 740 in his bag.";
string jasonHas = "Jason has 900 in his car.";
Regex dollarInsertion = new Regex(@"(?<start>^.*? has )(?<end>\d+ in his .*?$)", RegexOptions.Multiline);
Console.WriteLine(joeHas);
Console.WriteLine(jackHas);
Console.WriteLine(jimHas);
Console.WriteLine(jasonHas);
Console.WriteLine("--------------------------");
joeHas = dollarInsertion.Replace(joeHas, @"${start}$${end}");
jackHas = dollarInsertion.Replace(jackHas, @"${start}$-${end}");
jimHas = dollarInsertion.Replace(jimHas, @"${start}\$${end}");
jasonHas = dollarInsertion.Replace(jasonHas, @"${start}$kkkkkk----kkkk${end}").Replace("kkkkkk----kkkk", "");
Console.WriteLine(joeHas);
Console.WriteLine(jackHas);
Console.WriteLine(jimHas);
Console.WriteLine(jasonHas);
Output:
Joe has 500 in his wallet.
Jack has 500 in his pocket.
Jim has 740 in his bag.
Jason has 900 in his car.
--------------------------
Joe has ${end}
Jack has $-500 in his pocket.
Jim has \${end}
Jason has $900 in his car.
最佳答案
使用此替换模式:"${start}$$${end}"
双 $$
对 $
进行转义,以便将其视为文字字符。第三个 $
实际上是命名组 ${end}
的一部分。您可以在 MSDN Substitutions page 上阅读相关内容.
我会坚持使用上述方法。或者,您可以使用接受 MatchEvaluator
的 Replace
重载并连接您需要的内容,类似于以下内容:
jackHas = dollarInsertion.Replace(jackHas,
m => m.Groups["start"].Value + "$" + m.Groups["end"].Value);
关于正则表达式替换的 C# 美元问题,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/4338464/