public async Task <IActionResult> Detail(SiteDetailViewModel model)
        {
            if (ModelState.IsValid)
            {
                try
                {
                    var site = await _siteLookupService.GetByIdAsync(model.Id);

                    _mapper.Map <SiteDetailViewModel, Site>(model, site);

                    await _siteService.UpdateAsync(site);

                    ShowAlertSuccess($"Site '{site.Name}' successfully updated!");
                    return(RedirectToAction(nameof(Detail), new { id = site.Id }));
                }
                catch (GraException gex)
                {
                    ShowAlertDanger("Unable to update site: ", gex);
                }
            }
            PageTitle = $"Site management - {model.Name}";
            return(View(model));
        }
        private async void BackGroundRequestTask(IBackgroundTaskInstance taskInstance)
        {
            MessageRemind toast    = new MessageRemind(); //初始化消息提醒
            var           sitelist = DBHelper.GetAllSite();
            var           len      = sitelist.Count;      //使用foreach会出现不在期望中的异常
            SiteModel     _presite = new SiteModel();

            _presite = DBHelper.GetSiteById(4);            //这里是指定了precheck的id为4
            var _precolor = _presite.Last_request_result;  //如果percheck为错误 就不进行请求了

            if (_precolor != 0)
            {
                //遍历sitelist 根据协议进行请求
                for (int i = 0; i < len; i++)
                {
                    SiteModel si          = sitelist[i];
                    string    _protocol   = si.Protocol_type;
                    string    _address    = si.Site_address;
                    string    url         = _address;
                    bool      _is_Monitor = si.Is_Monitor;
                    if (!_is_Monitor)
                    {
                        continue;
                    }
                    if (!IPAddress.TryParse(url, out IPAddress reIP))
                    {
                        //如果输入的不是ip地址
                        //通过域名解析ip地址
                        //网址简单处理 去除http和https
                        var http  = url.StartsWith("http://");
                        var https = url.StartsWith("https://");
                        if (http)
                        {
                            url = url.Substring(7);//网址截取从以第一w
                        }
                        else if (https)
                        {
                            url = url.Substring(8);//网址截取从以第一w
                        }
                        IPAddress[] hostEntry = await Dns.GetHostAddressesAsync(url);

                        for (int m = 0; m < hostEntry.Length; m++)
                        {
                            if (hostEntry[m].AddressFamily == AddressFamily.InterNetwork)
                            {
                                reIP = hostEntry[m];
                                break;
                            }
                        }
                    }//根据地址解析出ipv4地址
                    switch (_protocol)//根据协议请求站点
                    {
                    case "HTTPS":
                        HTTPRequest hTTPs = HTTPRequest.Instance;
                        hTTPs.ProtocolType = TransportProtocol.https;    //更改协议类型
                        hTTPs.Uri          = _address;
                        bool httpsFlag = await hTTPs.MakeRequest();

                        //请求完毕
                        //处理数据
                        si.Request_interval = hTTPs.TimeCost;
                        si.Request_count   += 1;
                        if ("1002".Equals(hTTPs.Status))    //定义的超时状态码
                        {
                            //请求超时
                            si.Last_request_result = -1;
                        }
                        else
                        {
                            SiteDetailViewModel util = new SiteDetailViewModel(); //用于查看状态码
                            bool match = util.SuccessCodeMatch(si, hTTPs.Status); //匹配用户设定状态码
                            if (match)                                            //匹配为成功  否则为失败
                            {
                                si.Last_request_result = 1;
                            }
                            else
                            {
                                si.Last_request_result = 0;
                                toast.ShowToast(si);
                            }
                        }
                        break;

                    case "HTTP":
                        HTTPRequest hTTP = HTTPRequest.Instance;    //默认协议类型http
                        hTTP.Uri          = _address;
                        hTTP.ProtocolType = TransportProtocol.http;
                        bool httpFlag = await hTTP.MakeRequest();

                        //请求完毕
                        //处理数据
                        si.Request_interval = hTTP.TimeCost;
                        si.Request_count   += 1;
                        if ("1002".Equals(hTTP.Status))
                        {
                            //请求超时
                            si.Last_request_result = -1;
                        }
                        else
                        {
                            SiteDetailUtilImpl util = new SiteDetailUtilImpl();
                            bool match = util.SuccessCodeMatch(si, hTTP.Status);    //匹配用户设定状态码
                            if (match)
                            {
                                si.Last_request_result = 1;
                            }
                            else
                            {
                                si.Last_request_result = 0;
                            }
                        }
                        if (httpFlag == false)
                        {
                            toast.ShowToast(si);
                            si.Last_request_result = 0;
                        }
                        break;

                    case "DNS":
                        string     baiduDomain = "www.baidu.com";//设定一个网站供dns服务器进行解析
                        DNSRequest dNS         = new DNSRequest(reIP, baiduDomain);
                        bool       dnsFlag     = await dNS.MakeRequest();

                        //请求完毕
                        if ("1000".Equals(dNS.Status))
                        {
                            //dns正常
                            si.Last_request_result = 1;
                        }
                        else if ("1001".Equals(dNS.Status))
                        {
                            //unknown
                            si.Last_request_result = 2;
                        }
                        else if ("1002".Equals(dNS.Status))
                        {
                            //timeout
                            si.Last_request_result = -1;
                        }
                        si.Request_interval = dNS.TimeCost;
                        si.Request_count   += 1;
                        if (dnsFlag == false)
                        {
                            //消息提醒
                            si.Last_request_result = 0;
                            toast.ShowToast(si);
                        }
                        break;

                    case "ICMP":
                        ICMPRequest icmp     = new ICMPRequest(reIP);
                        bool        icmpFlag = icmp.DoRequest();
                        //请求完毕
                        RequestObj requestObj;    //用于存储icmp请求结果的对象
                        requestObj             = DataHelper.GetProperty(icmp);
                        si.Last_request_result = int.Parse(requestObj.Color);
                        si.Request_count      += 1;
                        si.Request_interval    = requestObj.TimeCost;
                        if (icmpFlag == false)
                        {
                            si.Last_request_result = 0;
                            toast.ShowToast(si);
                        }
                        break;

                    case "FTP":
                        var     json = si.ProtocolIdentification;
                        JObject js   = (JObject)JsonConvert.DeserializeObject(json);
                        //在此处加入type类型
                        string     username = js["username"].ToString();
                        string     password = js["password"].ToString();
                        FTPRequest fTP      = new FTPRequest(LoginType.Identify);
                        fTP.FtpServer = reIP;
                        fTP.Identification.Username = username;
                        fTP.Identification.Password = password;
                        bool ftpFlag = await fTP.MakeRequest();

                        //请求完毕
                        if ("1001".Equals(fTP.Status))
                        {
                            //置为错误
                            si.Last_request_result = 0;
                        }
                        else if ("1000".Equals(fTP.Status))
                        {
                            //置为成功
                            si.Last_request_result = 1;
                        }
                        else if ("1002".Equals(fTP.Status))
                        {
                            //超时异常
                            si.Last_request_result = -1;
                        }
                        si.Request_count   += 1;
                        si.Request_interval = fTP.TimeCost;
                        if (ftpFlag == false)
                        {
                            si.Last_request_result = 0;
                            toast.ShowToast(si);
                        }
                        break;

                    case "SMTP":
                        SMTPRequest sMTP     = new SMTPRequest(_address, si.Server_port);
                        bool        smtpFlag = await sMTP.MakeRequest();

                        //请求完毕

                        if ("1000".Equals(sMTP.Status))
                        {
                            si.Last_request_result = 1;
                        }
                        else if ("1001".Equals(sMTP.Status))
                        {
                            si.Last_request_result = 0;
                        }
                        else if ("1002".Equals(sMTP.Status))
                        {
                            si.Last_request_result = -1;
                        }
                        si.Request_count   += 1;
                        si.Request_interval = sMTP.TimeCost;
                        if (smtpFlag == false)
                        {
                            si.Last_request_result = 0;
                            toast.ShowToast(si);
                        }
                        break;

                    default:
                        break;
                    }
                    DBHelper.UpdateSite(si);
                }
            }
        }