c# .net 获取HTML meta标记中的内容

╰半夏微凉° 2023-01-13 04:10 130阅读 0赞

public class HtmlHelper
        {
            /// <summary>
            /// 使用举例： 
            /// 获取关键词 GetSingleTagValueByAttr(data, "meta", "name", "Keywords"); data是HTML源代码
            /// 获取描述GetSingleTagValueByAttr(data, "meta", "name", "Discription"); 
            /// </summary>
            /// <param name="inputstring"></param>
            /// <param name="tagName"></param>
            /// <param name="attrname"></param>
            /// <param name="key"></param>
            /// <returns></returns>
            public static string GetSingleTagValueByAttr(string inputstring, string tagName, string attrname, string key)
            {
                //string reg2 = $"(?<=meta name=\"keywords\" content=\").*?(?=\")";
                string regStr = $"(?<={tagName} {attrname}=\"{key}\" content=\").*?(?=\")";
                //string key_words = Regex.Match(inputstring, regStr).Value;
    
                //Regex reg = new Regex("<" + tagName + " [^<>]*>", RegexOptions.IgnoreCase);
                Regex reg = new Regex(regStr, RegexOptions.IgnoreCase);
                MatchCollection matchs = reg.Matches(inputstring);
                string result = string.Empty;
                foreach (Match match in matchs)
                {
                    string matchValue = match.Value;
                    if (!string.IsNullOrEmpty(matchValue))
                    {
                        return matchValue;
                    }
                    //Regex regValue = new Regex("content=".* "", RegexOptions.IgnoreCase);
                    //if (matchValue.ToLower().IndexOf(attrname.ToLower() + "="" + key.ToLower() + """) != -1)
                    //{
                    //    if (regValue.IsMatch(matchValue))
                    //    {
                    //        result = regValue.Match(matchValue).Value;
                    //        if (!string.IsNullOrEmpty(result))
                    //        {
                    //            //result = result.Replace("CONTENT=", "").Replace("content=", "").Replace(""", "");
    
    
                    //        }
                    //    }
                    //    return result;
                    //}
                }
                return null;
            }
        }