[转]使用.net里的WebClient自动下载baidu的mp3

WebClient webdown = new WebClient();
            string url = "http://list.mp3.baidu.com/topso/mp3topsong.html?id=1?top2";

            string tmp = webdown.DownloadString(url);
            // RTBInfo.Text = tmp;

            string scanStr = @"(?<urlstr>http://mp3.baidu.com/m[?]tn=baidump3&ct=(d+)(S+))(s*)(S+)>(?<songName>S+)<";//&(W<urlstr>+) target=_blank>(W<songName>+)</a>";
            Regex regScan = new Regex(scanStr, RegexOptions.IgnoreCase | RegexOptions.Compiled);
            MatchCollection matchCol_F = regScan.Matches(tmp);
            MatchCollection matchCol;
            MatchCollection matchCol_S;
          
            foreach (Match mat in matchCol_F)
            ...{

                string songName = mat.Groups["songName"].ToString();
                string songUrl = mat.Groups["urlstr"].ToString();
                songUrl = songUrl.Remove(songUrl.Length - 1, 1);

                if (songName == ")")
                ...{
                    continue;
                }
               
                RTBInfo.AppendText("下载歌曲:" + songName + " ");

                try
                ...{
                    tmp = webdown.DownloadString(songUrl);
                }
                catch
                ...{
                    continue;
                }
          //  http://220.181.38.82/m?ct=134217728&tn=baidusg,牛仔很忙  &word=mp3,http://jayhome.pengpeng.com/down/mp3/Y2Jja6OfrLKSm6Wpo5WBmap6oqGaZHqmMQ$$.mp3,,[%C5%A3%D7%D0%BA%DC%C3%A6+%D6%DC%BD%DC%C2%D7]&si=%C5%A3%D7%D0%BA%DC%C3%A6;;%D6%DC%BD%DC%C2%D7;;218633;;218633&lm=16777216
                scanStr = @"(?<urlstr>http://(S+)(d+)(D+)" + songName + @"(s*)(D+)mp3(S+)&lm=(d+))";
                regScan = new Regex(scanStr, RegexOptions.IgnoreCase | RegexOptions.Compiled);
                matchCol = regScan.Matches(tmp);
                if (matchCol.Count > 0)
                    songUrl = matchCol[0].Groups["urlstr"].ToString();
                else
                    continue;

                //RTBInfo.AppendText("下载地址2：" + songUrl + " ");
                try
                ...{
                    tmp = webdown.DownloadString(songUrl);
                }
                catch
                ...{
                    continue;
                }
                scanStr = @"(?<urlstr>http://(S+)mp3)";
                regScan = new Regex(scanStr, RegexOptions.IgnoreCase | RegexOptions.Compiled);
                matchCol_S = regScan.Matches(tmp);

                foreach (Match mat_S in matchCol_S)
                ...{
                    songUrl = mat_S.Groups["urlstr"].ToString();

                    // RTBInfo.AppendText("下载地址3：" + songUrl + " ");
                    RTBInfo.AppendText("下载中....");
                    try
                    ...{
                         if (File.Exists("d:\new\" + songName + ".mp3")) break;
                        webdown.DownloadFile(songUrl, "d:\new\" + songName + ".mp3");
                    }
                    catch(Exception ex)
                    ...{
                        RTBInfo.AppendText("下载失败 ");
                        continue;
                    }
                    RTBInfo.AppendText("下载成功 ");
                    break;
                }
            }
            RTBInfo.AppendText("下载结束 ");