public BaseResponse<string> DownloadPng(int appId, long userId, long drawId)
        {
            //var photoAlbum = dao.daoUserData.context.T_User_PhotoAlbum.Where(t => t.Type == 0 && t.DrawId == drawId).FirstOrDefault();
            var photoAlbum = dao.daoUserData.context.T_User_Gallery.Where(t => t.Type == 0 && t.DrawId == drawId).FirstOrDefault();
            if (photoAlbum == null)
            {
                return new BaseResponse<string>(ResonseCode.Error, "未找到画廊数据");
            }
            var obj = dao.daoLog.context.T_Draw_Download_log.Where(t => t.UserId == userId && t.DrawId == drawId).FirstOrDefault();
            var imgUrl = string.Empty;
            if (obj != null)
            {
                imgUrl = dao.daoData.context.T_Draw_Log.Where(it => it.Id == drawId).Select(t => t.TaskResult).FirstOrDefault();
                return new BaseResponse<string>(ResonseCode.Success, "", imgUrl);
            }
            var user = dao.daoUserData.context.T_Users_Data.Where(t => t.UserId == userId).FirstOrDefault();
            if (user == null)
            {
                return new BaseResponse<string>(ResonseCode.Error, "用户不存在");
            }
            var like = dao.daoUserData.context.T_User_Like.FirstOrDefault(it => it.DrawId == drawId && it.UserId == userId);
            if (like != null)
            {
                if (string.IsNullOrEmpty(imgUrl))
                {
                    imgUrl = dao.daoData.context.T_Draw_Log.Where(it => it.Id == drawId).Select(t => t.TaskResult).FirstOrDefault();
                }
                return new BaseResponse<string>(ResonseCode.Success, "", imgUrl);
            }
            var currency = user.Currency;
            if (currency <= 0)
            {
                return new BaseResponse<string>(ResonseCode.UserNotMoney, "用户金额不足");
            }
            if (obj == null)
            {
                var t_Draw_Download_Log = new T_Draw_Download_log
                {
                    UserId = userId,
                    DrawId = drawId,
                    GalleryId = photoAlbum.Id,
                    CreateDateTime = DateTime.Now,
                    LastDownloadDateTime = DateTime.Now,
                    DownloadCount = 1,
                    DownloadConsume = 1
                };
                dao.daoLog.Add(t_Draw_Download_Log);
            }
            else
            {
                obj.DownloadConsume += 1;
                obj.DownloadCount += 1;
                obj.LastDownloadDateTime = DateTime.Now;
                dao.daoLog.Update(obj);
            }
            new AccountBLL(dao).UpUserCurrencyInfo(userId, currency: -1);
            dao.daoLog.context.SaveChanges();
            if (string.IsNullOrEmpty(imgUrl))
            {
                imgUrl = dao.daoData.context.T_Draw_Log.Where(it => it.Id == drawId).Select(t => t.TaskResult).FirstOrDefault();
            }
            return new BaseResponse<string>(ResonseCode.Success, "", imgUrl);
        }