Linq-Detach方法--删除对象的时候如有关系导制错误去关系

 public static void Detatch(Object entity)
        {
            Type t = entity.GetType();
            System.Reflection.PropertyInfo[] properties = t.GetProperties(System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance);
            foreach (var property in properties)
            {
                string name = property.Name;
                if (property.PropertyType.IsGenericType &&
                property.PropertyType.GetGenericTypeDefinition() == typeof(EntitySet<>))
                {
                    property.SetValue(entity, null, null);
                }
            }
            System.Reflection.FieldInfo[] fields = t.GetFields(System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
            foreach (var field in fields)
            {
                string name = field.Name;
                if (field.FieldType.IsGenericType &&
                field.FieldType.GetGenericTypeDefinition() == typeof(EntityRef<>))
                {
                    field.SetValue(entity, null);
                }
            }
            System.Reflection.EventInfo eventPropertyChanged = t.GetEvent("PropertyChanged");
            System.Reflection.EventInfo eventPropertyChanging = t.GetEvent("PropertyChanging");
            if (eventPropertyChanged != null)
            {
                eventPropertyChanged.RemoveEventHandler(entity, null);
            }
            if (eventPropertyChanging != null)
            {
                eventPropertyChanging.RemoveEventHandler(entity, null);
            }
        }