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我有以下文本行（元标题）：

Buy [ProductName][Text] at a great price [/Text] from [ShopName] today.

我根据我拥有的价值观进行更换。

我让它按我的需要工作，但是我找不到正确的正则表达式来替换：

[Text] at a great price [/Text]

单词（在方括号之间的 nd 中）发生了变化，所以唯一保持不变的是：

[][/]

即我可能还想更换

[TestText]some test text[/TestText] with nothing.

我有这个工作：

System.Text.RegularExpressions.Regex.Replace(SEOContent, @"\[Text].*?\[/Text]", @"");

我假设的正则表达式：

[.*?].*?\[/.*?]

会工作，但它没有！- 我正在用 ASP.NET C# 编码提前谢谢，

戴夫

4

1 回答 1

1

使用命名捕获获取 [..] 的节点名称，然后使用 \k<..> 再次找到它。

(\[(?<Tag>[^\]]+)\][^\[]+\[/\k<Tag>\])

使用忽略模式空白和示例程序分解。

string pattern = @"
(                # Begin our Match
  \[             # Look for the [ escape anchor
  (?<Tag>[^\]]+) # Place anything that is not antother ] into the named match Tag
  \]             # Anchor of ]
  [^\[]+         # Get all the text to the next anchor
  \[/            # Anchor of the closing [...] tag
  \k<Tag>        # Use the named capture subgroup Tag to balance it out
  \]             # Properly closed end tag/node.
)                # Match is done";

string text = "[TestText]some test text[/TestText] with nothing.";

Console.WriteLine (Regex.Replace(text, pattern, "Jabberwocky", RegexOptions.IgnorePatternWhitespace));
// Outputs
// Jabberwocky with nothing.

顺便说一句，我实际上会创建一个标记化正则表达式（使用具有上述模式的正则表达式 If）并通过命名捕获识别部分来替换匹配项。然后在替换中使用匹配评估器替换已识别的标记，例如：

string pattern = @"
(?(\[(?<Tag>[^\]]+)\][^\[]+\[/\k<Tag>\]) # If statement to  check []..[/] situation
  (                                      # Yes it is, match into named captures
   \[
   (?<Token>[^\]]+)                      # What is the text inside the [ ], into Token
   \]
   (?<TextOptional>[^\[]+)               # Optional text to reuse
   \[
   (?<Closing>/[^\]]+)                   # The closing tag info
   \]
  )
|                                        # Else, let is start a new check for either [] or plain text
 (?(\[)                                  # If a [ is found it is a token.
   (                                     # Yes process token
    \[
    (?<Token>[^\]]+)                     # What is the text inside the [ ], into Token
    \]
   )
  |                                      # Or (No of the second if) it is just plain text
  (?<Text>[^\[]+)                        # Put it into the text match capture.
 )
)
";


string text = @"Buy [ProductName] [Text]at a great price[/Text] from [ShopName] today.";

Console.WriteLine (
Regex.Replace(text,
              pattern,
              new MatchEvaluator((mtch) =>
              {

                 if (mtch.Groups["Text"].Success)           // If just text, return it.
                     return mtch.Groups["Text"].Value;

                 if (mtch.Groups["Closing"].Success)       // If a Closing match capture group reports success, then process
                 {
                    return string.Format("Reduced Beyond Comparison (Used to be {0})", mtch.Groups["TextOptional"].Value);
                 }

                  // Otherwise its just a plain old token, swap it out.
                  switch ( mtch.Groups["Token"].Value )
                  {
                     case "ProductName" : return "Jabberwocky"; break;
                     case "ShopName"    : return "StackOverFlowiZon"; break;
                  }


                  return "???"; // If we get to here...we have failed...need to determine why.

              }),
              RegexOptions.IgnorePatternWhitespace | RegexOptions.ExplicitCapture));
// Outputs:
// Buy Jabberwocky Reduced Beyond Comparison (Used to be at a great price) from StackOverFlowiZon today.
于 2013-02-06T19:56:34.623 回答