IFeatureClassManage.UpdateExtent Method

Updates the XY, M, Z extent.

[Visual Basic .NET]
Public Sub UpdateExtent ( _
)

[C#]
public void UpdateExtent (
);

[C++]
HRESULT UpdateExtent(
void
);

Product Availability

Remarks

The UpdateExtent method recalculates the XY, Z and M extent for a feature class, based on the features contained within it. This extent is returned by the IGeodataset.Extent property. As new features are added to a feature class in a geodatabase, or a shapefile feature class, the extent is automatically expanded to accomodate them, however, when features are deleted, the extent does not shrink to eliminate areas where there are no longer features. This method will shrink the extent of the feature class to eliminate these areas.

The extent is a property of the feature class' schema, therefore, it requires an exclusive schema lock to execute, and is not an undoable operation. In the case of personal, File and ArcSDE geodatabase feature classes, the M and Z extent are not stored with the class. In the case of shapefiles, the M and Z extents are stored with the feature class.

When calling this method against an ArcSDE feature class, the extent is calculated based on the features that exist for that feature class in all versions. The extent will not shrink unless this method is called after the database has been compressed.

This method is not supported on coverage feature classes. A coverage's extent is maintained automatically during the editing process.

Note: The extents discussed here is not the same as the spatial reference domain. The domains (XY, Z, M) define the valid range of coordinate values that can be stored in a feature class. The extents reflect the actual range of coordinate values that exist within the feature class. The extents cannot be larger than the domains.

See Also

IFeatureClassManage Interface | IGeoDataset Interface | IFeatureClass Interface | ISchemaLock Interface