/// <summary>
        /// 在百度知道查询答案。
        /// </summary>
        /// <param name="sentence">要查询的句子</param>
        /// <param name="num">获取的答案数</param>
        /// <returns></returns>
        public static string[] getBaiduZhidaoAnswers(string sentence, int num = 10)
        {
            string url = string.Format("https://zhidao.baidu.com/search?word={0}", WebConnectHelper.UrlEncode(sentence));

            List <string> res  = new List <string>();
            string        html = WebConnectHelper.getData(url, Encoding.GetEncoding("gb2312"));
            HtmlDocument  hdoc = new HtmlDocument();

            hdoc.LoadHtml(html);

            try
            {
                var urls = hdoc.DocumentNode.SelectNodes("//a[@class=\"ti\"]");
                foreach (var aurl in urls)
                {
                    string dw       = ItemParser.removeBlank(aurl.GetAttributeValue("href", ""), true);
                    var    areslist = getBaiduZhidaoAnswersByUrl(dw);
                    if (areslist.Length > 0)
                    {
                        res.Add(areslist[0]);
                    }
                    // 暂时只查第一个
                    if (res.Count > 0)
                    {
                        break;
                    }
                }
            }
            catch { }

            return(res.ToArray());
        }
        /// <summary>
        /// 从百度知识图谱中寻找答案
        /// 基本就是把关键词放入百度搜索,然后看百度有没有智能返回的结果
        /// </summary>
        /// <param name="words"></param>
        /// <returns></returns>
        public static string[] getBaiduKGResult(string words)
        {
            List <string> reslist = new List <string>();
            string        askUrl  = "http://www.baidu.com/s?wd=" + WebConnectHelper.UrlEncode(words);
            string        html    = WebConnectHelper.getData(askUrl, Encoding.UTF8);
            HtmlDocument  hdoc    = new HtmlDocument();

            hdoc.LoadHtml(html);

            //统计数值
            try
            {
                string gdp = ItemParser.removeUnText(hdoc.DocumentNode.SelectSingleNode("//*[@class=\"op_gdp_subtitle\"]").InnerText);
                reslist.Add(gdp);
            }
            catch { }

            //图谱常识
            try
            {
                string common = ItemParser.removeUnText(hdoc.DocumentNode.SelectSingleNode("//*[@class=\"op_exactqa_s_answer\"]").InnerText);
                reslist.Add(common);
            }
            catch { }

            //股票
            try
            {
                string gp = ItemParser.removeUnText(hdoc.DocumentNode.SelectSingleNode("//*[@class=\"op_stockweakdemand_cur_num c-gap - right - small\"]").InnerText);
                reslist.Add(gp);
                string gpzf = ItemParser.removeUnText(hdoc.DocumentNode.SelectSingleNode("//*[@class=\"op_stockweakdemand_cur_info c-gap-icon-right-small\"]").InnerText);
                reslist.Add(gpzf);
            }
            catch { }

            //热线电话
            try
            {
                string rx = ItemParser.removeUnText(hdoc.DocumentNode.SelectSingleNode("//*[@class=\"op_kefupoly_td2\"]").InnerText);
                reslist.Add(rx);
            }
            catch { }


            //翻译
            try
            {
                string trans = ItemParser.removeUnText(hdoc.DocumentNode.SelectSingleNode("//*[@class=\"op_sp_fanyi_line_two\"]").InnerText);
                reslist.Add(trans);
            }
            catch { }

            //数学运算
            try
            {
                string trans = ItemParser.removeUnText(hdoc.DocumentNode.SelectSingleNode("//*[@style=\"font-size:1.4em;line-height:22px;padding-bottom:2px;width:474px;\"]").InnerText);
                reslist.Add(trans);
            }
            catch { }

            //汇率换算
            try
            {
                string hl = ItemParser.removeUnText(hdoc.DocumentNode.SelectSingleNode("//*[@class=\"op_exrate_result\"]").InnerText);
                reslist.Add(hl);
            }
            catch { }

            //单位换算
            try
            {
                string dw = ItemParser.removeUnText(hdoc.DocumentNode.SelectSingleNode("//*[@class=\"op-unit-result-single c-gap-left c-gap-right\"]").InnerText);
                reslist.Add(dw);
            }
            catch { }

            //邮编
            try
            {
                string dw = ItemParser.removeUnText(hdoc.DocumentNode.SelectSingleNode("//*[@class=\"op_post_content \"]").InnerText);
                reslist.Add(dw);
            }
            catch { }


            // 百度知道最佳答案
            // 去所跳转的页面上找答案
            try
            {
                string dw      = ItemParser.removeUnText(hdoc.DocumentNode.SelectSingleNode("//*[@class=\"op_best_answer_question_link\"]").GetAttributeValue("href", ""));
                var    answers = getBaiduZhidaoAnswers(dw)[0];
                reslist.Add(answers);
            }
            catch { }

            // 百度知道的推荐答案的第一个
            // 去所跳转的页面上找答案
            try
            {
                string dw      = ItemParser.removeUnText(hdoc.DocumentNode.SelectSingleNode("//*[@class=\"op_generalqa_answer c-gap-bottom-small op_generalqa_answer_first\"]").ChildNodes[3].FirstChild.GetAttributeValue("href", ""));
                var    answers = getBaiduZhidaoAnswersByUrl(dw)[0];
                reslist.Add(answers);
            }
            catch { }

            // 百度日历上的日子
            // 由于它是js生成的日历,所以需要从js里正则匹配一下
            try
            {
                Regex  reg  = new Regex("\"selectday\":\"([^\"]*?)\"", RegexOptions.None);
                string date = reg.Match(html).Groups[1].Value;
                if (!string.IsNullOrWhiteSpace(date))
                {
                    reslist.Add(date);
                }
            }
            catch { }


            return(reslist.ToArray());
        }
        //public static string[] getSearchResult(string words, int pagenum = 10)
        //{
        //    List<string> reslist = new List<string>();
        //    for (int i = 0; i < pagenum; i++)
        //    {

        //        string askUrl = "http://www.baidu.com/s?wd=" + WebConnectHelper.UrlEncode(words) + "&pn=" + (i * 10);
        //        string res = WebConnectHelper.getData(askUrl, Encoding.UTF8);
        //        res = res.Replace("\n", "").Replace("\r", "");
        //        HtmlDocument hdoc = new HtmlDocument();
        //        hdoc.LoadHtml(res);

        //        HtmlNodeCollection collection = hdoc.DocumentNode.SelectNodes("//*[@class=\"c-abstract\"]");
        //        if (collection != null)
        //        {
        //            foreach (HtmlNode node in collection)
        //            {
        //                reslist.Add(node.InnerText);
        //            }
        //            collection = hdoc.DocumentNode.SelectNodes("//*[@class=\"t\"]");
        //            foreach (HtmlNode node in collection)
        //            {
        //                reslist.Add(node.InnerText);
        //            }
        //        }
        //        else
        //        {
        //            return null;
        //        }

        //    }

        //    return reslist.ToArray();
        //}

        public string[] getWebsiteAnswer(string question)
        {
            List <string> answer = new List <string>();
            string        askUrl = "http://www.baidu.com/s?wd=" + WebConnectHelper.UrlEncode(question);
            string        res    = WebConnectHelper.getData(askUrl, Encoding.UTF8);

            res = res.Replace("\n", "").Replace("\r", "").Replace(" ", "");
            Regex reg = new Regex("class=\"op_exactqa_s_answer\">(.*?)</div>");

            if (reg.IsMatch(res))
            {
                //说明百度首页给出了智能答案
                res = reg.Match(res).Groups[1].ToString();
                reg = new Regex("target=\"_blank\">(.*?)</a>");
                if (reg.IsMatch(res))
                {
                    res = reg.Match(res).Groups[1].ToString();
                    answer.Add(res);
                }
            }
            else
            {
                //判断是否是百度统计相关答案
                reg = new Regex("<p class='op_gdp_subtitle'>(.*?)</p>");
                if (reg.IsMatch(res))
                {
                    res = reg.Match(res).Groups[1].ToString();
                    answer.Add(res);
                }
                else
                {
                    //判断是否是计算题答案
                    reg = new Regex("line-height:22px;padding-bottom:2px;width:474px;\">(.*?)</div>");
                    if (reg.IsMatch(res))
                    {
                        res = reg.Match(res).Groups[1].ToString().Replace("&nbsp;", " ");
                        answer.Add(res);
                    }
                    else
                    {
                        string tmpstr = "正在百度问题:" + question;
                        answer.Add(tmpstr);
                        //去百度知道查一波
                        askUrl = "http://zhidao.baidu.com/search?word=" + question;
                        res    = WebConnectHelper.getData(askUrl);
                        res    = res.Replace("\n", "").Replace("\r", "").Replace(" ", "");

                        //如果rank较低就舍弃
                        reg = new Regex("data-rank=\"(.*?)\"");
                        if (reg.IsMatch(res))
                        {
                            string rank      = reg.Match(res).Groups[1].ToString().Split(':')[0];
                            int    rankvalue = Int32.Parse(rank);
                            if (rankvalue <= 500)
                            {
                                //rank太低了,不再查询答案。
                                //return false;
                            }
                        }

                        reg = new Regex("data-log-area=\"list\">(.*?)</a>");
                        if (reg.IsMatch(res))
                        {
                            res = reg.Match(res).Groups[1].ToString();
                            reg = new Regex("href=\"(.*?)\"");
                            if (reg.IsMatch(res))
                            {
                                //从知道首页找到最接近的答案的url
                                askUrl = reg.Match(res).Groups[1].ToString();
                                res    = WebConnectHelper.getData(askUrl).Replace("\n", "").Replace("\r", "").Replace(" ", "");

                                Regex[] regs = new Regex[] {
                                    //被采纳答案
                                    new Regex("wgt-best(.*?)i-quality-icon"),
                                    new Regex("wgt-best(.*?)answer-share-widget"),
                                    //尝试优质答案
                                    new Regex("quality-content-detailcontent\">(.*?)</div>"),
                                    //尝试网友推荐答案
                                    new Regex("wgt-recommend(.*?)i-quality-icon")
                                };
                                bool ismatch = false;
                                foreach (var treg in regs)
                                {
                                    if (treg.IsMatch(res))
                                    {
                                        //tmpOutputSentence.Add(res);
                                        res     = treg.Match(res).Groups[1].ToString();
                                        ismatch = true;
                                        break;
                                    }
                                }
                                if (ismatch)
                                {
                                    reg = new Regex("<pre(.*?)>(.*?)</pre>");
                                    if (reg.IsMatch(res))
                                    {
                                        res = reg.Match(res).Groups[2].ToString();
                                        res = res.Replace("<br>", "\r\n");
                                        res = res.Replace("<br/>", "\r\n");
                                        res = replaceImageWords(res);
                                        answer.Add(res);
                                    }
                                }



                                //{

                                //    reg = ;
                                //    if (reg.IsMatch(res))
                                //    {
                                //        res = reg.Match(res).Groups[1].ToString();
                                //        res = res.Replace("<br>", "\r\n");
                                //        res = res.Replace("<br/>", "\r\n");
                                //        res = replaceImageWords(res);
                                //        tmpOutputSentence.Add(res);
                                //        isa = true;
                                //    }
                                //    else
                                //    {
                                //        ;
                                //        if (reg.IsMatch(res))
                                //        {
                                //            res = reg.Match(res).Groups[1].ToString();
                                //            reg = new Regex("<pre(.*?)>(.*?)</pre>");
                                //            if (reg.IsMatch(res))
                                //            {
                                //                res = reg.Match(res).Groups[2].ToString();
                                //                res = res.Replace("<br>", "\r\n");
                                //                res = res.Replace("<br/>", "\r\n");
                                //                res = replaceImageWords(res);
                                //                tmpOutputSentence.Add(res);
                                //                isa = true;
                                //            }
                                //        }
                                //    }
                                //}
                            }
                        }
                    }
                }
            }



            return(answer.ToArray());
        }
        /// <summary>
        /// 根据百度知道的页面来查找是否有最佳答案或者用户认可答案之类的
        /// </summary>
        /// <param name="url"></param>
        /// <returns></returns>
        public static string[] getBaiduZhidaoAnswersByUrl(string url)
        {
            List <string> res = new List <string>();

            // 弱智百度的编码是gb2312
            string       html = WebConnectHelper.getData(url, Encoding.GetEncoding("gb2312"));
            HtmlDocument hdoc = new HtmlDocument();

            hdoc.LoadHtml(html);

            // 新版最佳答案
            try
            {
                string dw = hdoc.DocumentNode.SelectSingleNode("//*[@class=\"best-text mb-10\"]").InnerHtml;
                dw = replaceImageWords(dw);

                var           tmp = getText(dw);
                StringBuilder sb  = new StringBuilder();
                foreach (var t in tmp)
                {
                    if (!string.IsNullOrWhiteSpace(t.Trim()))
                    {
                        sb.Append(t + "\r\n");
                    }
                }
                sb.Replace("\r\n\r\n", "\r\n");
                res.Add(sb.ToString());
            }
            catch { }

            return(res.ToArray());

            //res = reg.Match(res).Groups[1].ToString();
            //reg = new Regex("href=\"(.*?)\"");
            //if (reg.IsMatch(res))
            //{
            //    //从知道首页找到最接近的答案的url
            //    askUrl = reg.Match(res).Groups[1].ToString();
            //    res = WebConnectHelper.getData(askUrl).Replace("\n", "").Replace("\r", "").Replace(" ", "");

            //    Regex[] regs = new Regex[]{
            //                        //被采纳答案
            //                        new Regex("wgt-best(.*?)i-quality-icon"),
            //                        new Regex("wgt-best(.*?)answer-share-widget"),
            //                        //尝试优质答案
            //                        new Regex("quality-content-detailcontent\">(.*?)</div>"),
            //                        //尝试网友推荐答案
            //                        new Regex("wgt-recommend(.*?)i-quality-icon")

            //                    };
            //    bool ismatch = false;
            //    foreach (var treg in regs)
            //    {
            //        if (treg.IsMatch(res))
            //        {
            //            //tmpOutputSentence.Add(res);
            //            res = treg.Match(res).Groups[1].ToString();
            //            ismatch = true;
            //            break;
            //        }
            //    }
            //    if (ismatch)
            //    {
            //        reg = new Regex("<pre(.*?)>(.*?)</pre>");
            //        if (reg.IsMatch(res))
            //        {
            //            res = reg.Match(res).Groups[2].ToString();
            //            res = res.Replace("<br>", "\r\n");
            //            res = res.Replace("<br/>", "\r\n");
            //            res = replaceImageWords(res);
            //            answer.Add(res);
            //        }
            //    }

            //}
        }