如何添加到ICollection列表并将其保存到数据库而又不会出现对象处置异常？ （实体框架）

Question

可以说我们有一个这样的类：

public class SampleClass
{

    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int ID { get; set; }

    public virtual ICollection<ScoreData> ScoreData{ get; set; }
}

还有另一个这样的类：

public class ScoreData
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int Id {get; set;}
    public int subSectionScore {get; set;}

    public int SampleClassID { get; set; }
    public virtual SampleClass SampleClass { get; set; }
}

为什么这会引发对象处置异常，并且如何解决该异常？

internal static void CalculatesubSectionScores(ref List<SampleClass> sampleClassData)
{

    foreach (var item in sampleClassData)
    {
        item.ScoreData= new List<ScoreData>();

        /* code in second foreach accesses another objects item to 
           use for each sub sections calculations*/

        foreach ()
        {
           var scoringData = new ScoreData();
           var score = 0.0;
           scoringData.subSectionScore = score;

           item.ScoreData.Add(scoringData);
        }
    }

我已经从此类中删除了大多数逻辑，只是为了关注手头的问题。

Answer 1

在添加之前声明ScoreData

internal static void CalculatesubSectionScores(ref List<SampleClass> sampleClassData)
{

    foreach (var item in sampleClassData)
    {
        item.ScoreData= new List<ScoreData>();

        /* code in second foreach accesses another objects item to 
           use for each sub sections calculations*/

        item.ScoreData = new List<ScoreData>();  // Add This Line

        foreach ()
        {
           var scoringData = new ScoreData();
           var score = 0.0;
           scoringData.subSectionScore = score;

           item.ScoreData.Add(scoringData);
        }
    }
}