这是我不相信的代码。请检查我作为实体Collection的参数传递的方式。请注意第一个子程序,我从examProduced传递实体Collection Exercises。在另一个中,我将从查询中的函数返回值。
public ExamProduced GetExamProduced(XElement xml)
{
var examProduced = new ExamProduced
{
ExamProducedID = (int)xml.Attribute("ExamID"),
Date = (DateTime)xml.Attribute("Date"),
Seed = (int)xml.Attribute("Seed"),
//Exercises = GetExercises(xml)
};
GetExercises(xml, examProduced.Exercises);
return examProduced;
}
public void GetExercises(XElement xml, EntityCollection<Exercise> entityCollection)
{
var objs =
from objective in xml.Descendants("Objective")
where (bool)objective.Attribute("Produced")
let id = (int)objective.Attribute("ID")
let id2 = (Objective)entityService.Objectives.Where(o => o.ObjectiveID == id).FirstOrDefault()
select new Exercise
{
Objective = id2,
MakeUp = ...
Quantify = ...
Score = ...
};
foreach (var exercise in objs)
{
entityCollection.Add(exercise);
}
}
如果没有,我会收到错误。像这样的代码。
public ExamProduced GetExamProduced(XElement xml)
{
var examProduced = new ExamProduced
{
ExamProducedID = (int)xml.Attribute("ExamID"),
Date = (DateTime)xml.Attribute("Date"),
Seed = (int)xml.Attribute("Seed"),
Exercises = GetExercises(xml)
};
return examProduced;
}
public EntityCollection<Exercise> GetExercises(XElement xml)
{
var objs =
from objective in xml.Descendants("Objective")
where (bool)objective.Attribute("Produced")
let id = (int)objective.Attribute("ID")
select new Exercise
{
ExerciseID = id,
MakeUp = (bool)objective.Attribute("MakeUp"),
Quantify = (byte)(int)objective.Attribute("Quantify"),
Score = (float)objective.Elements().Last().Attribute("Result")
};
var entityCollection = new EntityCollection<Exercise>();
foreach (var exercise in objs)
entityCollection.Add(exercise);
return entityCollection;
}
我得到的错误如下:
InvalidOperationException未处理。
无法将对象添加到EntityCollection或 的EntityReference。附加到ObjectContext的对象不能 被添加到不是的EntityCollection或EntityReference 与源对象相关联。