使用正则表达式从字符串中获取值

Having a html string that looks like this:

有一个看起来像这样的html字符串:

<div class="mainClass" id="mainId" title="This is the title" customtag="+500"></div>

I want to get 500

我想要500

What I have done so far:

到目前为止我做了什么:

string k = @"<div class=""mainClass"" id=""mainId"" title=""This is the title"" customtag=""+500""></div>";
//or
string k = "<div class=\"mainClass\" id=\"mainId\" title=\"This is the title\" customtag=\"+500\"></div>";

// Using this regex (?<=customtag="\+)\d+(?=">)

Regex regex = new Regex(@"(?<=customtag=""\+)\d+(?="">)");
Match match = regex.Match(k);
Console.WriteLine(match.Value);

After running it, match.Value is empty even if when testing the regex in a text editor it correctly finds the string I'm looking for.

运行之后,即使在文本编辑器中测试正则表达式时,match.Value也是空的,它正确地找到了我正在寻找的字符串。

2 个解决方案

#1

string s = "<div class=\"mainClass\" id=\"mainId\" title=\"This is the title\" customtag=\"+500\"></div>";
        Regex regex = new Regex("customtag=\"\\+(\\d+)\"");
        if (regex.Match(s).Groups.Count >= 1)
        {
            Console.WriteLine(regex.Match(s).Groups[1].Value);
        }

#2

Another approach with XmlDocument - IMO the cleaner way:

使用XmlDocument的另一种方法 - IMO更清洁的方式:

string k = "<div class=\"mainClass\" id=\"mainId\" title=\"This is the title\" customtag=\"+500\"></div>";
System.Xml.XmlDocument doc = new System.Xml.XmlDocument();
doc.LoadXml(k);
string result = doc.DocumentElement.Attributes["customtag"].Value;

Fiddle: https://dotnetfiddle.net/pAHXMp