How to modify / update Feature attribute using API in Map 3D?

By Partha Sarkar

You would like to programmatically modify / update the Feature Object's fields i.e. it's attribute data using Geospatial Platform API in Map 3D.

In the screenshot below, we can see a Feature Object with ID = 10 and its Length property = 10.1234; using API we will update it’s value to 12.0.

Here is a VB.NET code snippet which demonstrates how to programmatically modify / update the Feature Object's fields i.e. it's attribute data using Geospatial Platform API in Map 3D :

        Try

 

            Dim map As AcMapMap = AcMapMap.GetCurrentMap()

            Dim resId As MgResourceIdentifier = Nothing

            Dim layerName As String = "API_Poly_Objects"

            Dim className As String = ""

 

            ' Get the resource Id and class name of the layer on which we want to update

            Dim layers As MgLayerCollection = map.GetLayers()

            Dim layer As MgLayerBase = Nothing

            Dim iCount As Integer = Nothing

            For iCount = 0 To (layers.Count)

                If (layers.GetItem(iCount).Name.ToLower() = layerName.ToLower()) Then

                    layer = layers.GetItem(iCount)

                    resId = New MgResourceIdentifier(layer.GetFeatureSourceId().ToString())

                    Exit For

                End If

            Next iCount

 

            If layer Is Nothing Then

                ed.WriteMessage(vbCrLf + "Layer Not Found ! ")

                Exit Sub

            End If

 

            ' Create a new Property colleaction Object

            Dim propColl As MgPropertyCollection = New MgPropertyCollection()

 

            ' Create STNAME prop to Update it

            Dim lengthProp As MgDoubleProperty = New MgDoubleProperty("Length", 12.0)

 

            'Add the length property to property collection

            propColl.Add(lengthProp)

 

            ' Define a filter to get the object whose property we want to update

            '' Feature ID = 10 is specific to a sample SDF

            Dim filterText As String = "ID=10"

 

            'Create the UpdateFeatures object for the update

            Dim updateFeatures As MgUpdateFeatures = New MgUpdateFeatures(layer.FeatureClassName, propColl, filterText)

 

            ' Create a command collection for the update

            Dim commands As MgFeatureCommandCollection = New MgFeatureCommandCollection()

            commands.Add(updateFeatures)

 

            ' Commit the Update

            fs.UpdateFeatures(resId, commands, True)

            layer.ForceRefresh()

            trans.Commit()

 

        Catch ex As MgException

            ed.WriteMessage(ex.Message.ToString())

 

        Finally

            trans.Dispose()

        End Try