整数通过TempData @ C#ASP.NET MVC3 EntityFramework

时间:2012-05-07 08:36:47

标签: c# asp.net-mvc entity-framework-4 tempdata

我有从TempData探测整数的问题,因为它将DempData [“sth”]视为对象,而不是整数本身。这是我的Create方法,我将整数发送到TempData:

public ActionResult Create(int CustomerId, int qSetId, int Count)
{
    qSet qset = db.qSets.Find(qSetId);
    TempData["qSetId"] = qset.Id;
    Customer customer = db.Customers.Find(CustomerId);
    TempData["CustomerId"] = customer.Id;
    List<Relation> relations = db.Relations.Where(r => r.qSetId.Equals(qSetId)).ToList<Relation>();
    Question question = new Question();
    List<Question> questions = new List<Question>();
    foreach (Relation relation in relations)
    {
        question = db.Questions.Find(relation.QuestionId);
        if (questions.Contains<Question>(question).Equals(false))
            questions.Add(question);
    }
    if (questions.Count<Question>().Equals(Count).Equals(false))
    {
        TempData["QuestionId"] = questions[Count].Id;
        TempData["QuestionType"] = questions[Count].Type;
        ViewBag["QuestionContent"] = questions[Count].Content;
        TempData["Count"] = Count + 1;
        return View();
    }
    else
    {
        return RedirectToAction("ThankYou");
    }
}

这是探测这些数据的另一种方法:

[HttpPost]
public ActionResult Create(Answer answer)
{                               
    answer.QuestionId = TempData["QuestionId"];
    answer.CustomerId = TempData["CustomerId"];

    if (ModelState.IsValid)
    {
        db.Answers.Add(answer);
        db.SaveChanges();
        return RedirectToAction("Create", new { CustomerId = TempData["CustomerId"], qSetId = TempData["qSetId"], Count = TempData["Count"] });
    }

    ViewBag.CustomerId = new SelectList(db.Customers, "Id", "eAdress", answer.CustomerId);
    ViewBag.QuestionId = new SelectList(db.Questions, "Id", "Name", answer.QuestionId);
    return View(answer);
}

错误出现在:

answer.QuestionId = TempData["QuestionId"];
answer.CustomerId = TempData["CustomerId"];

然后这样:

  

无法将类型'object'隐式转换为'int'。存在显式转换(您是否错过了演员?)

任何帮助?

3 个答案:

答案 0 :(得分:8)

对此的解决方案称为“拆箱”。它是从对象 int 的直接演员:

answer.QuestionId = (int)TempData["QuestionId"];

答案 1 :(得分:1)

我的代码中遇到了同样的问题。

这两种解决方案都有效:

    answer.QuestionId = Convert.ToInt32(TempData["QuestionId"];

    answer.QuestionId = (int)TempData["QuestionId"];

但是,(int)强制转换在每个实例中都不起作用,因为并非每个对象都可以隐式转换为int。因此,使用Convert.ToInt32()

会更安全

答案 2 :(得分:0)

int id = Convert.ToInt32(TempData["QuestionId"].ToString());