Question

我有一个像

这样的字符串

<link rel='stylesheet' href='/abc/def/ghi/default.css' type='text/css' media='screen' />

现在，我想提取“/abc/def/ghi/default.css”并将其传递给函数foo

void foo(string str)
{

//some logic
return str; //suppose it returns /abc/def/ghi/default.css/v=123
}

我想将它追溯到我原来的字符串，如

<link rel='stylesheet' href='/abc/def/ghi/default.css/v=123' type='text/css' media='screen' />

我尝试使用substring，但是alwals内容更改，我可以从“href”开始查找字符串，但我不知道href会有多长。

Answer 1

如果您在＆＃39; href＆＃39;之后识别开始和结束单引号，您仍然可以使用子字符串。字符串中的标识符。

public string foo(string inputString)
        {
            string result = "";
            int hrefIndex = inputString.IndexOf("href=");
            int firstQuoteIndexAfterHref = -1;
            int secondQuoteIndexAfterHref = -1;

            if (hrefIndex != -1)
            {
                firstQuoteIndexAfterHref = inputString.IndexOf("'", hrefIndex + 1);
                Console.Out.WriteLine("hrefIndex={0}, firstQuoteIndex={1}", hrefIndex, firstQuoteIndexAfterHref);
                if (firstQuoteIndexAfterHref != -1)
                {
                    secondQuoteIndexAfterHref = inputString.IndexOf("'", firstQuoteIndexAfterHref + 1);
                    result = string.Format("{0}/v=123",inputString.Substring(firstQuoteIndexAfterHref, secondQuoteIndexAfterHref - firstQuoteIndexAfterHref + 1));
                }
            }
            return result;
        }

Answer 2

你可以这样做：

public string foo(string str)
{
    var StartIndex = str.IndexOf("href");
    var firstapostrophe = str.IndexOf("'",StartIndex);
    var secondapostrophe = str.IndexOf("'", firstapostrophe);
    var result = str.Replace(str.Substring(firstapostrophe, secondapostrophe - 2),
    str.Substring(firstapostrophe, secondapostrophe - 2) + "/v=123");
    return result; 
}

Answer 3

简单地将其视为xml，请看一下：

using System;
using System.Xml;
using System.Xml.Linq;

public class Program
{
    public static void Main()
    {
        var s = "<link href='aaa' />";
        var doc = XDocument.Parse(s);
        var link = doc.Element("link");
        var href = link.Attribute("href");

        href.Value = "bbb";
        s = doc.ToString();
        Console.WriteLine(s);
    }
}

字符串修改和替换c＃

3 个答案: