Each Snap field in a document corresponds to a specific SnapEntity that is returned by the ISnapFieldOwner.ParseField method. Any modification of an entity at runtime must be wrapped in the SnapEntity.BeginUpdate and EndUpdate method calls.
The following requirements apply to the proper customization of a SnapEntity at runtime.
To learn whether or not the customization is opened for an entity, consult its SnapEntity.Active property value.
To learn whether or not the customization is opened for a specific entity, use the ISnapFieldOwner.ActiveEntity property.
To open an entity for runtime customization, call its SnapEntity.BeginUpdate method.
To apply the new settings, call the EndUpdate method.
Do not call the EndUpdate method for a parent entity until there is no active nested entity left within it.
If a document contains multiple entities that are nested inside each other (e.g., in case of a master-detail report), only the outermost (parent) field in this document is active.
To modify the content of a nested field within a parent field’s document, do the following.
- Obtain the nested field from a corresponding SnapDocument.
- Parse the field by calling the ISnapFieldOwner.ParseField method that returns the appropriate SnapEntity.
- Call the SnapEntity.BeginUpdate method of the returned entity.
- After making the required changes, make sure to call the EndUpdate method for the nested entity.
- Call the EndUpdate method for the parent entity.