Question

我需要在一个文本块中突出显示搜索字词。

我最初的想法是通过搜索术语循环。但是有更简单的方法吗？

以下是我正在考虑使用循环...

public string HighlightText(string inputText)
{
    string[] sessionPhrases = (string[])Session["KeywordPhrase"];
    string description = inputText;

    foreach (string field in sessionPhrases)
    {
        Regex expression = new Regex(field, RegexOptions.IgnoreCase);
        description = expression.Replace(description, 
                                         new MatchEvaluator(ReplaceKeywords));
    }
    return description;
}

public string ReplaceKeywords(Match m)
{
    return "<span style='color:red;'>" + m.Value + "</span>";
}

Answer 1

您可以使用以下内容替换循环：

string[] phrases = ...
var re = String.Join("|", phrases.Select(s => Regex.Escape(s)).ToArray());
text = Regex.Replace(re, text, new MatchEvaluator(SomeFunction), RegexOptions.IgnoreCase);

Answer 2

延伸Qtax的回答：

phrases = ...

// Use Regex.Escape to prevent ., (, * and other special characters to break the search
string re = String.Join("|", phrases.Select(s => Regex.Escape(s)).ToArray());

// Use \b (expression) \b to ensure you're only matching whole words, not partial words
re = @"\b(?:" +re + @")\b"

// use a simple replacement pattern instead of a MatchEvaluator
string replacement = "<span style='color:red;'>$0</span>";
text = Regex.Replace(re, text, replacement, RegexOptions.IgnoreCase);

如果您已经在HTML中替换数据，那么使用Regex替换内容中的任何内容可能不是一个好主意，您最终可能会得到：

<<span style='color:red;'>script</span>>

如果有人正在搜索术语脚本。

为防止这种情况发生，you could use the HTML Agility Pack in combination with Regex。

You might also want to check out this post which deals with a very similar issue

正则表达式使用字符串数组替换matchEvaluator

2 个答案: