[英]The relationship between the two objects cannot be defined - why?
我正在提交一個包含用戶ID和以豎線分隔的數字集的表單。
該模型如下所示:
public class SeasonPassData
{
public int UserID { get; set; }
public string SpaceNumbers { get; set; }
}
即將移交給該控制器:
[HttpPost]
public ActionResult SignUp(SeasonPassData data)
{
var user = db.Users.Find(data.UserID);
List<SeasonPass> passes = new List<SeasonPass>();
char[] delimiter = { '|' };
var numbers = data.SpaceNumbers.Split(delimiter).Select(n => Convert.ToInt32(n)).ToArray();
foreach(int number in numbers)
{
passes.Add(new SeasonPass { SpaceNumber=number, User = user });
}
passes.ForEach(p => db.SeasonPasses.Add(p));
db.SaveChanges();
return RedirectToAction("Confirmation", "Home");
}
並且應該創建並保存SeasonPasses:
public class SeasonPass
{
public int ID { get; set; }
public int SpaceNumber { get; set; }
public virtual User User { get; set; }
}
但是,這是passes.ForEach(p => db.SeasonPasses.Add(p));
不斷突襲此異常:
System.Data.Entity.dll中發生類型為'System.InvalidOperationException'的異常,但未在用戶代碼中處理
附加信息:由於兩個對象被附加到不同的ObjectContext對象,因此無法定義它們之間的關系。
我該如何解決?
我根據評論對這些更改進行了嘗試。 它似乎仍然不起作用...
[HttpPost]
public ActionResult SignUp(SeasonPassData data)
{
using(var context = new TTUContext())
{
var user = context.Users.Find(data.UserID);
List<SeasonPass> passes = new List<SeasonPass>();
char[] delimiter = { '|' };
var numbers = data.SpaceNumbers.Split(delimiter).Select(n => Convert.ToInt32(n)).ToArray();
foreach (int number in numbers)
{
passes.Add(new SeasonPass { SpaceNumber = number, User = user });
}
foreach (var pass in passes)
{
context.SeasonPasses.Add(pass);
}
context.SaveChanges();
}
return RedirectToAction("Confirmation", "Home");
}
令您驚訝的是,您正在執行的操作不起作用,但是這是避免該問題的一種方法。
添加public int UserID { get; set; }
public int UserID { get; set; }
public int UserID { get; set; }
設置為SeasonPass
並將其設置為分配關系,而不是設置User
。
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