/// <summary>  
/// 获取字符中指定标签的值  
/// </summary>  
/// <param name="str">字符串</param>  
/// <param name="title">标签</param>  
/// <param name="attrib">属性名</param>  
/// <returns>属性</returns>  
public static string GetTitleContent(string str, string title, string attrib)
{
string tmpStr = string.Format("<{0}[^>]*?{1}=(['""]?)(?<url>[^'""\\s>]+)\\1[^>]*>", title, attrib);   
Match TitleMatch = Regex.Match(str, tmpStr, RegexOptions.IgnoreCase);
string result = TitleMatch.Groups["url"].Value;
return result;
}


/// <summary>
/// 获取字符中指定标签的值
/// </summary>
/// <param name="str">字符串</param>
/// <param name="title">标签</param>
/// <returns>值</returns>
public static string GetTitleContent(string str, string title)
{
string tmpStr = string.Format("<{0}[^>]*?>(?<Text>[^<]*)</{1}>", title, title);
Match TitleMatch = Regex.Match(str, tmpStr, RegexOptions.IgnoreCase);
string result = TitleMatch.Groups["Text"].Value;
return result;
}