替換除中間行之外的換行符 <pre> 標簽

Question

我想要替換/刪除給定字符串中的所有換行符，除了嵌套在<pre>標記內的換行符。 所以對於以下字符串：

var text = @"
    Some contents which is formatted
    over multiple
    lines but contains a 
    <pre>
        tag which has
        also has
        multiple line breaks.
    </pre>
";

我想刪除所有換行符，除了嵌套在pre標簽中的換行符：

Regex.Replace(text, "\n", "<br />");

Answer 1

使用負向前看，您仍然可以在一行中執行：

text = Regex.Replace(text, "\n(?![^<]*</pre>)", "<br />");

這是一些測試代碼，包含多個<pre>標簽的更好樣本：

var text = @"
    Some contents which is formatted
    over multiple
    lines but contains a 
    <pre>
        tag which has
        also has
        multiple line breaks.
    </pre>
    foo 1
    bar 1
    <pre>
        tag which has
        also has
        multiple line breaks.
    </pre>
    foo 2
    bar 2
";
text = Regex.Replace(text, "\n(?![^<]*</pre>)", "<br />");
Console.WriteLine(text);

輸出：

<br />    Some contents which is formatted<br />    over multiple<br />    lines but contains a <br />    <pre>
    tag which has
    also has
    multiple line breaks.
</pre><br />    foo 1<br />    bar 1<br />    <pre>
    tag which has
    also has
    multiple line breaks.
</pre><br />    foo 2<br />    bar 2<br />  

Answer 2

不漂亮，但對我有用。

    static void Main(string[] args)
        {
            var text = @"
    Some contents which is formatted
    over multiple
    lines but contains a 
    <pre>
        tag which has
        also has
        multiple line breaks.
    </pre>
";
            int pre_tag_ini = text.IndexOf("<pre>");
            int pre_tag_fim = text.IndexOf("</pre>");
            string result = Regex.Replace(text.Substring(0, pre_tag_ini), "\r\n", "<br />");
            result += text.Substring(pre_tag_ini, pre_tag_fim - pre_tag_ini);;
            result += Regex.Replace(text.Substring(pre_tag_fim, text.Length - pre_tag_fim), "\r\n", "<br />");

            Console.Write(result);
            Console.ReadLine();
        }