C#获取HTML文本的第一张图片与截取内容摘要示例代码

#region 获取第一张图片/// <summary>/// 获取HTML文本的图片地址/// </summary>/// <param name="content"></param>/// <returns></returns>//// public ArrayList getimgurl(string html){  ArrayList resultStr = new ArrayList();  Regex r = new Regex(@"<IMG[^>] src=s*(?:´(?<src>[^´] )´|""(?<src>[^""] )""|(?<src>[^>s] ))s*[^>]*>", RegexOptions.IgnoreCase);//忽视大小写  MatchCollection mc = r.Matches(html);  foreach (Match m in mc)  {    resultStr.Add(m.Groups["src"].Value.ToLower());  }  if (resultStr.Count > 0)  {    return resultStr;  }  else  {    resultStr.Clear();    return resultStr;  }}#endregion

 #region 新闻内容摘要/// <summary>/// 新闻内容摘要/// </summary>/// <param name="sString"></param>/// <param name="nLeng"></param>/// <returns></returns>public string GetContentSummary(string content, int length, bool StripHTML){  if (string.IsNullOrEmpty(content) || length == 0)    return "";  if (StripHTML)  {    Regex re = new Regex("<[^>]*>");    content = re.Replace(content, "");    content = content.Replace("　", "").Replace(" ", "");    if (content.Length <= length)      return content;    else      return content.Substring(0, length)  "……";  }  else  {    if (content.Length <= length)      return content;    int pos = 0, npos = 0, size = 0;    bool firststop = false, notr = false, noli = false;    StringBuilder sb = new StringBuilder();    while (true)    {      if (pos >= content.Length)        break;      string cur = content.Substring(pos, 1);      if (cur == "<")      {        string next = content.Substring(pos  1, 3).ToLower();        if (next.IndexOf("p") == 0 && next.IndexOf("pre") != 0)        {          npos = content.IndexOf(">", pos)  1;        }        else if (next.IndexOf("/p") == 0 && next.IndexOf("/pr") != 0)        {          npos = content.IndexOf(">", pos)  1;          if (size < length)            sb.Append("<br/>");        }        else if (next.IndexOf("br") == 0)        {          npos = content.IndexOf(">", pos)  1;          if (size < length)            sb.Append("<br/>");        }        else if (next.IndexOf("img") == 0)        {          npos = content.IndexOf(">", pos)  1;          if (size < length)          {            sb.Append(content.Substring(pos, npos - pos));            size = npos - pos  1;          }        }        else if (next.IndexOf("li") == 0 || next.IndexOf("/li") == 0)        {          npos = content.IndexOf(">", pos)  1;          if (size < length)          {            sb.Append(content.Substring(pos, npos - pos));          }          else          {            if (!noli && next.IndexOf("/li") == 0)            {              sb.Append(content.Substring(pos, npos - pos));              noli = true;            }          }        }        else if (next.IndexOf("tr") == 0 || next.IndexOf("/tr") == 0)        {          npos = content.IndexOf(">", pos)  1;          if (size < length)          {            sb.Append(content.Substring(pos, npos - pos));          }          else          {            if (!notr && next.IndexOf("/tr") == 0)            {              sb.Append(content.Substring(pos, npos - pos));              notr = true;            }          }        }        else if (next.IndexOf("td") == 0 || next.IndexOf("/td") == 0)        {          npos = content.IndexOf(">", pos)  1;          if (size < length)          {            sb.Append(content.Substring(pos, npos - pos));          }          else          {            if (!notr)            {              sb.Append(content.Substring(pos, npos - pos));            }          }        }        else        {          npos = content.IndexOf(">", pos)  1;          sb.Append(content.Substring(pos, npos - pos));        }        if (npos <= pos)          npos = pos  1;        pos = npos;      }      else      {        if (size < length)        {          sb.Append(cur);          size ;        }        else        {          if (!firststop)          {            sb.Append("……");            firststop = true;          }        }        pos ;      }    }    return sb.ToString();  }}#endregion