public async Task <ActionResult> Detail(string cityName) { if (ControllerContext.HttpContext.Session["history"] == null) { ControllerContext.HttpContext.Session["history"] = Guid.NewGuid().ToString("N"); } var rt = await _weather.GetInfoAsync(cityName); if (!_weather.IsError) { LogChangeHelp lh = new LogChangeHelp(); lh.ChangeDB(cityName, rt, (string)Session["history"], _uw.LogRepository); } ViewBag.City = cityName; ViewBag.IsError = _weather.IsError; return(View(rt)); }