C＃正则表达式 - 不匹配我的字符串 [英] C# regex - not matching my string

问题描述

我使用.NET 2.0与C＃的WinForms。我有正则表达式的一个大问题。我想一个冒号在一个简单的字符串添加到4个或更多字母的单词。它应该只追加冒号一次，之后的代码不应该附加任何更多。

I'm using NET 2.0 with WinForms on C#. I am having a big problem with regex. I'm trying to add a colon to 4 or more letter words in a simple string. It should only append the colon once, after that the code shouldn't append any more.

Regex lbls = new Regex(@"^\s*(?<lbl>[A-Za-z0-9_]{4,})", RegexOptions.Multiline); // Use a regex to obtain all 4 letter words in string
MatchCollection matches = lbls.Matches(text); // text is my string

foreach (Match m in matches)
{
  string mm = m.Groups["lbl"].Value; // Matches are stored in this group.
  if (!Regex.IsMatch(text, @"^\s*\b" + mm + @":\b", RegexOptions.Multiline))
  {
    text = Regex.Replace(text, @"\b" + mm + @"\b", mm + ":", RegexOptions.Multiline);
  }
}

假设字符串为测试。这意味着输出应该是TEST：这是。但是，如果代码运行一次，文应保持TEST：但事实并非如此，这是TEST ::来代替。不断添加冒号。为什么是这样？我如果语句看起来完全正确的。

Suppose the string is "TEST". That means the output should be "TEST:" which it is. However if code is run once more, the text should remain "TEST:" but it does not and it is "TEST::" instead. Colons keep being added. Why is this? My if statement looks fully correct.

推荐答案

在运行代码的第一次，你要搜索的价值TEST在输入（这是简单的TEST），并用TEST替换它并附加一个冒号到结束

The first time you run your code, you're searching for the value "TEST" in your input (which is simply "TEST") and replacing it with "TEST" and appending a colon to the end.

因此在第一次迭代后，其结果将是TEST。

So after the first iteration, the result will be "TEST:".

在运行代码的第二次，你正在寻找在你的输入值TEST（也就是现在的TEST ），并用测试和附加冒号到端代替。

The second time you run your code, you're searching for the value "TEST" in your input (which is now "TEST:") and replacing it with "TEST" and appending a colon to the end.

所以第二迭代后，其结果将是TEST ::

So after the second iteration, the result will be "TEST::".

好像你只需要附加一个冒号，只当没有冒号存在（也许？）结束。

Seems like you only want to append a colon to the end only when no colon exists(maybe?).

尝试改变你的如果行此...

Try changing you "if" line to this...

if ( !Regex.IsMatch( text , @"\b" + mm + @"\b:" , RegexOptions.Multiline ) )

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