ITopologyClassEvents Interface

Provides access to events that occur with a topology class.

When To Use

Use ITopologyClassEvents for building ClassExtensions when you don't want to rely on catching the ITopologyExtensionEvents OnValidate event. This is handy when you need to implement geodatabase-level customization that will not be application-specific.

Members

	Name	Description
	OnValidate	This event is fired when the topology containing the class is validated.

ITopologyClassEvents.OnValidate Method

This event is fired when the topology containing the class is validated.

Public Sub OnValidate ( _
    ByVal validatedArea As IGeometry _
)

public void OnValidate (
    IGeometry validatedArea
);

Remarks

The OnValidate event is fired each time a dirty area is validated in the topology in which the class is participating. Handlers are provided with an IGeometry object corresponding to the dirty areas that were validated. The IGeometry object may represent a single or multi-part polygon or a collection of polygons. In some cases, using the OnValidate method on feature classes in a Topology may result in a situation where the Topology will always have a Dirty Area such as if the purpose of listening to the OnValidate event is to act on another feature class in the Topology and perform some action on the features in that class. For example, an extension that listens to the OnValidate event in order to derive features for a feature class by aggregating the features in the class that is validated. If the derived features are in a feature class that is in the Topology, the result of the OnValidate event will be a Topology that will always contain a dirty area. The derived feature class should not be in the topology in order for this example to be applicable.

Classes that implement ITopologyClassEvents

Classes	Description

Remarks

The ITopologyClassEvents interface provides access to the OnValidate event which is fired each time a dirty area is validated in the topology in which the class is participating. The event returns an IGeometry object corresponding to the area that was validated.