Linq到SQL-审计跟踪(在SubmitChanges中查找旧值)

目前我正在寻找一种在[context].SubmitChanges（）.中查找实体旧值的方法

据我所知，只有新的价值观出现了。我真的需要对数据库进行查询以获取实体的旧值吗？

GertArnold的解决方案：

    public override void SubmitChanges(System.Data.Linq.ConflictMode failureMode)
                {
                    // Get the changeset
                    ChangeSet changeSet = this.GetChangeSet();
                    // Put the updated objects into a IEnumerable
                    IEnumerable<object> updatedEntities = changeSet.Updates;
                    foreach (var entity in updatedEntities.Where(entity => AuditTypes.Contains(entity.GetType())))
                    {
                        var old = this.GetTable(entity.GetType()).GetModifiedMembers(entity);
                        // Do something with the old values
                    }
                    // Save the changes
                    base.SubmitChanges(failureMode);
                }