正则表达式匹配未被括号括起来的字符串

Question

如果文本没有被方括号括起来,我必须解析一个带有关键字的文本.我要与关键字匹配带.此外,必须有在两侧字边界带.

下面是一些例子,其中有不是关键字:

• [与]
• [与]
• [sometext with sometext]
• [sometext with]
• [有些文字]

以下是使用 IS关键字的一些示例

• 同
• 用
• 你好
• 你好世界
• 你好[世界]与你好
• 你好[世界]与你好[世界]

有人帮忙吗？提前致谢.

Answer 1

您可以查找该单词with并查看其左侧最近的支架不是左括号,并且右侧最近的支架不是右括号:

Regex regexObj = new Regex(
    @"(?<!     # Assert that we can't match this before the current position:
     \[        #  An opening bracket
     [^[\]]*   #  followed by any other characters except brackets.
    )          # End of lookbehind.
    \bwith\b   # Match ""with"".
    (?!        # Assert that we can't match this after the current position:
     [^[\]]*   #  Any text except brackets
     \]        #  followed by a closing bracket.
    )          # End of lookahead.", 
    RegexOptions.IgnorePatternWhitespace);
Match matchResults = regexObj.Match(subjectString);
while (matchResults.Success) {
    // matched text: matchResults.Value
    // match start: matchResults.Index
    // match length: matchResults.Length
    matchResults = matchResults.NextMatch();
}

环视表达式不会在换行符处停止; 如果您希望单独评估每一行,请使用[^[\]\r\n]*而不是 [^[\]]*.