[英]The relationship between the two objects cannot be defined - why?
我正在提交一个包含用户ID和以竖线分隔的数字集的表单。
该模型如下所示:
public class SeasonPassData
{
public int UserID { get; set; }
public string SpaceNumbers { get; set; }
}
即将移交给该控制器:
[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");
}
并且应该创建并保存SeasonPasses:
public class SeasonPass
{
public int ID { get; set; }
public int SpaceNumber { get; set; }
public virtual User User { get; set; }
}
但是,这是passes.ForEach(p => db.SeasonPasses.Add(p));
不断突袭此异常:
System.Data.Entity.dll中发生类型为'System.InvalidOperationException'的异常,但未在用户代码中处理
附加信息:由于两个对象被附加到不同的ObjectContext对象,因此无法定义它们之间的关系。
我该如何解决?
我根据评论对这些更改进行了尝试。 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");
}
令您惊讶的是,您正在执行的操作不起作用,但是这是避免该问题的一种方法。
添加public int UserID { get; set; }
public int UserID { get; set; }
public int UserID { get; set; }
设置为SeasonPass
并将其设置为分配关系,而不是设置User
。
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