IGeoDataset Interface

Provides access to members that provide information about a Geographic Dataset.


Name Description
Read-only property Extent The extent of the GeoDataset.
Read-only property SpatialReference The spatial reference of the GeoDataset.

IGeoDataset.Extent Property

The extent of the GeoDataset.

Public ReadOnly Property Extent As IEnvelope
public IEnvelope Extent {get;}


The IGeoDataset::Extent property returns an envelope representing the maximum extent of data which has been stored in the dataset.

Consider the following scenario. A new feature class has features added to it. The IGeoDataset::Extent is then requested and an envelope is returned. The extents of the envelope returned are represented by the red box in the image below.

The red box represents the IGeoDataset extent

If a portion of the features were then deleted and the extent is again requested an envelope with the exact same extents as during the first request would be returned (see image below). This is because the deletion of features does not shrink the extent. However all additions of features outside the red box would increase the envelope returned to encompass the newly added features.

The red box represents the IGeoDataset extent after some of the features have been deleted

If you would like to update the IGeoDataset::Extent property to reflect the current features in your dataset please see IFeatureClassManage::UpdateExtent (also see IFeatureClassLoad). In the image below the extent has been updated and a new envelope is being returned.

The red box represents the IGeoDataset extent after it has been updated

ESRI's GroupLayer implements this property differently from most other layer coclasses. When you instantiate a new GroupLayer, this property will return a valid envelope with zero height and width. With most other newly instantiated layers (for example FeatureLayer, RasterLayer, TinLayer), this property initally returns Nothing.

IGeoDataset.SpatialReference Property

The spatial reference of the GeoDataset.

Public ReadOnly Property SpatialReference As ISpatialReference
public ISpatialReference SpatialReference {get;}


This property is read only. For layers, when the first layer is added to ArcMap, its spatial reference is read by this property, and the map is set to this spatial reference.

Instances of the esriCarto.GroupLayer class will return null for this property, as a group layer can contain multiple datasets with different spatial references.

Modifications to a spatial reference returned by this property will not be persisted. To modify the spatial reference of a dataset, the IGeoDatasetSchemaEdit and IGeoDatasetSchemaEdit2 interfaces should be used.

Classes that implement IGeoDataset

Classes Description
BimModelObject (esriDataSourcesFile) Esri BIM File Model class.
FeatureClass Esri Feature Class object.
FunctionRasterDataset (esriDataSourcesRaster) A class for a function raster dataset.
MosaicRaster (esriDataSourcesRaster) A mosaic of rasters.
Raster (esriDataSourcesRaster) An in-memory representation of a dynamic raster that can perform resampling and reprojection.
RasterBand (esriDataSourcesRaster) A representation of a single band of a raster dataset on disk.
RasterCatalog A collection of raster datasets in a Geodatabase table.
RasterCatalogTable (esriDataSourcesRaster) A special type of table used to display multiple rasters simultaneously.
RasterDataset (esriDataSourcesRaster) A representation of a raster dataset on disk.
SdeRasterCatalogTable (esriDataSourcesRaster) A class for managing 8.x ArcSDE RasterCatalogs.
Tin The Esri TIN component.
XYEventSource XY event source object.


This interface provides access to information about spatial datasets, in particular their spatial reference and geographic extent. All layers also implement this interface.

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