Provides access to the Feature Extent Map Area Interface.
When To Use
Use IFeatureExtent to zoom to selected features of a layer.
Members
Name | Description | |
---|---|---|
DefaultScale | Scale at which the extent of a single point is drawn. | |
ExpandRatio | Ratio used to expand the extent. | |
FeatureIDs | The set of feature IDs. | |
LayerID | The ID of the layer. | |
MapName | Name of the map (data frame). |
IFeatureExtent.DefaultScale Property
Scale at which the extent of a single point is drawn.
Public Property DefaultScale As Double
public double DefaultScale {get; set;}
Remarks
Use DefaultScale to control the map scale when zooming to a single point feature. The DefaultScale value only affects conditions where a single point feature is selected. This value will be ignored when selecting multiple points or when selecting other feature types. If this value is not set and FeatureIDs is comprised of a single point feature, the new spatial extent may be too large.
IFeatureExtent.ExpandRatio Property
Ratio used to expand the extent.
Public Property ExpandRatio As Double
public double ExpandRatio {get; set;}
Remarks
Use ExpandRatio to add a "buffer" around the requested geographic extent. For example, an ExpandRatio value of 1.5 will expand the map extent by 1.5 times.ExpandRatio should be used to ensure that the set of features can be viewed easily. Otherwise, some features may be at the very edge of the displayed map extent. If the ExpandRatio is not set (the default value is 1) some of the selected features will be located at the very edge of the map image. A number greater than 1 will "zoom out", providing a spatial buffer around the selected features. A number less than 1 will "zoom in".
IFeatureExtent.FeatureIDs Property
The set of feature IDs.
Public Property FeatureIDs As IFIDSet
public IFIDSet FeatureIDs {get; set;}
IFeatureExtent.LayerID Property
The ID of the layer.
Public Property LayerID As Integer
public int LayerID {get; set;}
IFeatureExtent.MapName Property
Name of the map (data frame).
Public Property MapName As String
public string MapName {get; set;}
Classes that implement IFeatureExtent
Classes | Description |
---|---|
FeatureExtent | The Feature Extent coclass allows you to zoom to selected features in a layer. |
Remarks
To use a FeatureExtent, the properties MapName, LayerID and FeatureIDs need to be set. You are likely to get unexpected results if these properties are not set. The ExpandRatio and DefaultScale properties are optional. If the ExpandRatio is not set some of the selected features will be located at the very edge of the map image. The DefaultScale value only affects conditions where a single point feature is selected. This will be the map scale in which the map will zoom to when a single point is selected.
The following sample code shows how to zoom to selected features of a layer using IFeatureExtent. It assumes that you already have a valid MapServer and MapDescription object, and that you are not working with a server context. However, if you are developing an ArcGIS for Server application using a server context, you should not use New to create local ArcObjects, but you should always create objects within the server by calling CreateObject on IServerContext.