Provides access to members that return properties common to rings and polygons.
Product Availability
Description
Use the IArea interface to get the Area of a Geometry. It can also be used to get the Centroid point and Label point for a Geometry.
Members
| Description | ||
|---|---|---|
 |
Area | The area. |
|
Centroid | The center of gravity (centroid). |
|
LabelPoint | A point guaranteed to be inside this area. |
 |
QueryCentroid | Copies the centroid of this area to the specified point. |
|
QueryLabelPoint | Copies to the input point a point guaranteed to be inside this area. |
CoClasses that implement IArea
| CoClasses and Classes | Description |
|---|---|
| Envelope | A rectangle with sides parallel to a coordinate system defining the extent of another geometry; optionally has min and max measure, height and ID attributes. |
| GeoEllipse (esriDefenseSolutions) | Its a spheroidal ellipse. |
| GeoPolygon (esriDefenseSolutions) | Its a spheroidal polygon. |
| MultiPatch | A collection of surface patches. |
| Polygon | A collection of rings ordered by their containment relationship; optionally has measure, height and ID attributes. |
| Ring | An area bounded by one, closed sequence of connected segments; optionally has measure, height and ID attributes at each vertex. |
[C#]// The example shows how to get the properties for a selected polygon in // an ArcMap edit session. public void showPolygonProperties() { //get editor extension UID editorUID = new UIDClass(); editorUID.Value = "esriEditor.Editor"; IEditor editor = m_application.FindExtensionByCLSID(editorUID) as IEditor; if (editor.SelectionCount != 1) { System.Windows.Forms.MessageBox.Show("Start Editor and select one polygon"); return; } IEnumFeature selectedFeatures = editor.EditSelection; IPoint centerPoint = new ESRI.ArcGIS.Geometry.Point(); IPoint labelPoint = new ESRI.ArcGIS.Geometry.Point(); IFeature feature = selectedFeatures.Next(); while (feature != null) { if (feature.Shape.GeometryType == esriGeometryType.esriGeometryPolygon) { IArea area = feature.Shape as IArea; String message = "+++Polygon.IArea properties...\n" + "Area = " + area.Area + "\n" + "Center.X = " + area.Centroid.X + "\n" + "Center.Y = " + area.Centroid.Y + "\n" + "LabelPoint.X = " + area.LabelPoint.X + "\n" + "LabelPoint.Y = " + area.LabelPoint.Y; area.QueryCentroid(centerPoint); area.QueryLabelPoint(labelPoint); message = message + "\n" + "+++Polygon.IArea Queries..." + "\n" + "Center = " + centerPoint.X + "," + centerPoint.Y + "\n" + "Label = " + labelPoint.X + "," + labelPoint.Y; System.Windows.Forms.MessageBox.Show(message); } feature = selectedFeatures.Next(); } }
' The example shows how to get the properties for a selected polygon in
' an ArcMap edit session.
Public Sub t_IArea_polygon()
Dim pID As New UID
pID = "esriEditor.editor"
Dim pEditor As IEditor
Dim pApp As IApplication
Set pApp = Application
Set pEditor = pApp.FindExtensionByCLSID(pID)
If pEditor.SelectionCount <> 1 Then
MsgBox "select one polygon"
Exit Sub
End If
Dim pEnumFeat As IEnumFeature
Dim pFeature As IFeature
Dim i As Long
Set pEnumFeat = pEditor.EditSelection
Dim pArea As IArea
Dim pCenter As IPoint
Dim pLabel As IPoint
Set pCenter = New Point
Set pLabel = New Point
Set pFeature = pEnumFeat.Next
While Not pFeature Is Nothing
If pFeature.Shape.GeometryType = esriGeometryPolygon Then
Set pArea = pFeature.Shape
MsgBox "+++Polygon::IArea properties..." & vbCrLf _
& "Area = " & pArea.Area & vbCrLf _
& "Center.X = " & pArea.Centroid.X & vbCrLf _
& "Center.Y = " & pArea.Centroid.Y & vbCrLf _
& pArea.LabelPoint.X & vbCrLf _
& "LabelPoint.Y = " & pArea.LabelPoint.Y
pArea.QueryCentroid pCenter
pArea.QueryLabelPoint pLabel
MsgBox "+++Polygon::IArea Queries..." & vbCrLf _
& "Center = " & pCenter.X & "," & pCenter.Y & vbCrLf _
& "Label = " & pLabel.X & "," & pLabel.Y & vbCrLf
End If
Set pFeature = pEnumFeat.Next
Wend
End Sub