Question

 public ActionResult CreateArea(int? cityid)
        {
            if (cityid == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }
            var Name = db.Cities.Where(c => c.CityID == cityid)
                     .Select(x => x.CityName);
            ViewBag.message = Name;
            Area city = db.Areas.Find(cityid);
            return View(city);
        }

这个我的ActionMethod在这个我想通过viewbag传递查看的cityname但我的LINQ查询错误它不显示cityname而不是这个查询打印到我的view.plz帮我纠正我的LINQ查询。

Answer 1

您错过了“{1}}，.ToList()，.First()，.FirstOrDefault()等”表达式“的”执行“.....

.Single()

Answer 2

 var Name = db.Cities.Select(x => x.CityName).Where(c => c.CityID == cityid).FirstOrDefault()

            ViewBag.message = Name;
            Area city = db.Areas.Find(cityid);
            return View(city);

尝试这样的事情

Answer 3

您需要从查询中返回单个结果，然后访问name属性：

  var Name = db.Cities.Single(c => c.CityID == cityid).CityName;

Answer 4

这可能对您有帮助！

  var model =  model.Where(i => i.ParamKey == Key).First();

LINQ选择查询与Where条件返回单个记录

4 个答案: