private async void DownLoadImage()
        {
            string content = "";

            content = await NetWork.getHttpWebRequest(Api.StartPageImagApi, PostORGet : 1, fulluri : true);

            if (string.IsNullOrWhiteSpace(content))
            {
                return;
            }
            ImageList imageList = JsonConvert.DeserializeObject <ImageList>(content);
            //创建加入数据库的临时变量
            Database dbTemp = new Database();

            foreach (var item in imageList.Data)
            {
                DateTime tempTime = StartPageHelp.GetTime(item.StartTime);
#if DEBUG
                string imageName = item.ImageUrl.Substring(item.ImageUrl.LastIndexOf('/') + 1);
                dbTemp.Name      = item.Name;
                dbTemp.StartTime = item.StartTime;
                dbTemp.TargetUrl = item.TargetUrl;
                dbTemp.Id        = item.Id;
                dbTemp.Url       = StartPageHelp.ImagesPath.Path + "\\" + imageName;
                if (StartPageHelp.InserDatabase(dbTemp))
                {
                    await StartPageHelp.DownloadPictrue(item.ImageUrl, imageName);
                }
#else
                if (tempTime > DateTime.Now)
                {
                    string imageName = item.ImageUrl.Substring(item.ImageUrl.LastIndexOf('/') + 1);
                    dbTemp.Name      = item.Name;
                    dbTemp.StartTime = item.StartTime;
                    dbTemp.TargetUrl = item.TargetUrl;
                    dbTemp.Id        = item.Id;
                    dbTemp.Url       = StartPageHelp.ImagesPath.Path + "\\" + imageName;
                    if (StartPageHelp.InserDatabase(dbTemp))
                    {
                        await StartPageHelp.DownloadPictrue(item.ImageUrl, imageName);
                    }
                }
#endif
            }
        }
        /// <summary>
        /// 判断数据库是否有图片
        /// </summary>
        private void SetImage()
        {
            Database temp       = new Database();
            string   deviceType = AnalyticsInfo.VersionInfo.DeviceFamily;

            if (StartPageHelp.GetImageFromDB(ref temp))
            {
                Model.HasPictrue    = false;
                Model.PictrueSource = temp.Url;
                if (deviceType == "Windows.Mobile")
                {
                    Model.StretchMode = Stretch.Uniform;
                    Model.HorMode     = HorizontalAlignment.Stretch;
                    Model.VerMode     = VerticalAlignment.Stretch;
                    StatusBar.GetForCurrentView().HideAsync().AsTask();
                }
                else
                {
                    Model.StretchMode = Stretch.Uniform;
                    Model.HorMode     = HorizontalAlignment.Center;
                    Model.VerMode     = VerticalAlignment.Stretch;
                }
            }
            else
            {
                Model.HasPictrue    = true;
                Model.PictrueSource = @"Assets/SplashScreen.png";

                if (deviceType == "Windows.Mobile")
                {
                    Model.StretchMode = Stretch.Uniform;
                    Model.HorMode     = HorizontalAlignment.Center;
                    Model.VerMode     = VerticalAlignment.Center;
                    StatusBar.GetForCurrentView().HideAsync().AsTask();
                }
                else
                {
                    ApplicationView.GetForCurrentView().TitleBar.BackgroundColor =
                        ApplicationView.GetForCurrentView().TitleBar.ButtonBackgroundColor = Windows.UI.Color.FromArgb(255, 5, 139, 254);
                    Model.StretchMode = Stretch.None;
                    Model.HorMode     = HorizontalAlignment.Center;
                    Model.VerMode     = VerticalAlignment.Stretch;
                }
            }
        }