修复c＃中的unicode编码问题

Question

我正在尝试从html文件中提取文本。喜欢这个页面。

https://artkapakistan.wordpress.com/2013/01/08/debunking-the-myth-of-the-artist/

我使用HtmlAgilipack从entry-content类中获取内部html，然后删除html标记。编码似乎有问题因为我得到了奇怪的字符。 •确切地说。根据我的在线搜索，第一个是单引号，第二个是不间断的空间。我尝试使用正则表达式替换单引号和双引号但没有成功。

  s1 = Regex.Replace(s1, "’|‘", "'");
  s1 = Regex.Replace(s1, "“|”", "\"");

但我无法取代他们。编码似乎存在一些问题。在正则表达式和字符串替换之下，我不是那么精通。你能帮助我解决这个问题吗？我试图找出'修复c＃中的unicode问题'但没有成功。 非常感谢这方面的任何帮助。

编辑： 以下是我如何检索内部html和文本。

text = document.DocumentNode.SelectSingleNode(postBodyClass).InnerHtml;
                    text = RemoveHTMLTags(text);
                    text = RemoveHTMLPunctuation(text);
public static string RemoveHTMLPunctuation(string input)
        {
            string s1 = input;
            s1 = System.Net.WebUtility.HtmlDecode(s1);
            //replace html left right single double quotation marks
            s1 = Regex.Replace(s1, "€¦", "…");
            s1 = Regex.Replace(s1, "’", "'");
            s1 = Regex.Replace(s1, "€œ|€", "\"");
            //replace unicode right and left quotation marks with straight quotation
            string s2 = s1.Replace("“", "\x201c");
            string s3 = s2.Replace("’", "\x2019");
            string s4 = s3.Replace("”", "\x201d");
            string s5 = s4.Replace("…", "\x2026");
            string s6 = s5.Replace(" ", "");
            s6 = s6.Replace("«", "");
            string s7 = s6.Replace(""", "\"");
            string s8 = s7.Replace("&", "&");
            s8 = Regex.Replace(s8, "&[a-z]+;", "");
            s8 = Regex.Replace(s8, "'", "'");
            //remove non breaking space
            s8 = Regex.Replace(s8, " |Â", "");
            //add missing spaces after punctuation marks
            //s8 = Regex.Replace(s8, "([\\.\\?,;:])(\\w+)", "$1 $2");
            return s8;
        }
        public static string RemoveHTMLTags(string input)
        {
            string s1 = input;
            //remove script tag and everything within.
            s1 = Regex.Replace(s1, "\\<script\\s*[^><]+\\>[^><]*\\</\\s*script\\>", "");
            s1 = Regex.Replace(s1, "\\<\\s*br\\s*/*\\s*\\>", Environment.NewLine);
            //add new line for div p or li tag
            s1 = Regex.Replace(s1, "\\<\\s*/(div|p|li)\\s*\\s*\\>", Environment.NewLine);
            s1 = Regex.Replace(s1, "\\>=", "");
            string s2 = Regex.Replace(s1, "&ldquo;", "\x201c");
            string s3 = Regex.Replace(s2, "\\<[Aa]([^><]+|\\s*)\\>.*\\</\\s*[Aa]\\s*\\>", "");
            string s4 = Regex.Replace(s3, "\\<[^<>]+\\>", "");
            string s5 = Regex.Replace(s4, "\\|", "");
            //replace multiple lines with 1 line
            s5 = Regex.Replace(s5, "(\\r\\n|\\r|\\n){2,}", Environment.NewLine);
            //any annoying text put it here to replace from post text
            //s5 = Regex.Replace(s5, "Copyright (c) 2008 Saadia Malik", "");
            s5 = s5.Trim();
            return s5;
        }