C# EntityEntry.UpdateComplexObjectSnapshot方法代码示例

        // See IChangeTrackingStrategy documentation
        public void SetCurrentValue(EntityEntry entry, StateManagerMemberMetadata member, int ordinal, object target, object value)
        {
            // If the target is the entity, then this is a change to a member on the entity itself rather than
            // a change to some complex type property defined on the entity.  In this case we can use the change tracking
            // API in the normal way.
            if (ReferenceEquals(target, entry.Entity))
            {
                // equivalent of EntityObject.ReportPropertyChanging()
                ((IEntityChangeTracker)entry).EntityMemberChanging(member.CLayerName);
                member.SetValue(target, value);
                // equivalent of EntityObject.ReportPropertyChanged()
                ((IEntityChangeTracker)entry).EntityMemberChanged(member.CLayerName);

                if (member.IsComplex)
                {
                    // This is required because the OSE contains a separate cache of user objects for
                    // complex objects such that original values can be looked up correctly.
                    entry.UpdateComplexObjectSnapshot(member, target, ordinal, value);
                }
            }
            else
            {
                // Must be a complex type.  We would like to do this:
                // ((IEntityChangeTracker)entry).EntityComplexMemberChanging(topLevelMember.CLayerName, target, member.CLayerName);
                // ((IEntityChangeTracker)entry).EntityComplexMemberChanged(topLevelMember.CLayerName, target, member.CLayerName);
                //
                // However, we have no way of getting the topLevelMember.CLayerName.  This is because the value record does not
                // contain any reference to its parent.  (In non-POCO, ComplexObject takes care of this.)
                // Therefore, in this case we are going to just call a localized DetectChanges to make sure that changes in the
                // complex types are found.
                //
                // Note that this case only happens when the entity is POCO and complex types are set through the CurrentValues
                // object.  This is probably not a very common pattern.
                member.SetValue(target, value);
                if (entry.State
                    != EntityState.Added)
                {
                    // Entry is not Detached - checked in ValidateState() in EntityEntry.SetCurrentEntityValue
                    entry.DetectChangesInProperties(true);
                }
            }
        }