Split a polyline at the vertices using ArcObjects

Summary

Note:
This article pertains to ArcGIS versions 8.x and 9.x. Later versions of ArcGIS may contain different functionality, as well as different names and locations for menus, commands and geoprocessing tools.

This article contains an ArcObjects code sample that demonstrates how to split a polyline at the vertices, creating separate lines from each line segment.

Note: 
Support for Visual Basic for Applications (VBA) for ArcMap and ArcCatalog ended with the ArcGIS 10.2.2 release, and Esri has not included VBA compatibility setups since version 10.5. See: ArcGIS Desktop and VBA Moving Forward

Procedure

1. Start ArcMap.
2. Create a new UIButtonControl: How To: Create a new UIButtonControl​

Note:
For more information on creating a UIControl, see the ArcGIS Desktop Help topic: 'Creating custom commands with VBA and UI Controls'

3. Right-click the UIButtonControl and select View Source.
4. Copy and paste the following code into the UIButtonControl's click event.

   Dim pMxDoc As IMxDocument
   Dim pFeatureClass As IFeatureClass
   Dim pFeatureLayer As IFeatureLayer
   Dim pFeatureCursor As IFeatureCursor
   Dim pOutFeatureCursor As IFeatureCursor
   Dim pFeature As IFeature
   Dim pOutFeatureBuffer As IFeatureBuffer
   Dim pSegmentCollection As ISegmentCollection
   Dim pSegment As ISegment
   Dim pPointCollection As IPointCollection
   Dim i As Integer
   Dim index As Integer
   Dim numFeatures As Integer

   'Split lines for selected layer
   Set pMxDoc = ThisDocument

   If Not pMxDoc.SelectedLayer Is Nothing Then
     Set pFeatureLayer = pMxDoc.SelectedLayer
   Else
      MsgBox "Please select layer to split"
      Exit Sub
   End If

   Set pFeatureClass = pFeatureLayer.FeatureClass
   Set pFeatureCursor = pFeatureClass.Update(Nothing, False)
   Set pOutFeatureCursor = pFeatureClass.Insert(True)
   Set pFeature = pFeatureCursor.NextFeature
   numFeatures = pFeatureClass.FeatureCount(Nothing)

   'Loop through the features and split each feature at
   'it's vertices then copy attributes and shape to new feature
   For index = 0 To numFeatures - 1
      Set pSegmentCollection = pFeature.Shape

      For i = 0 To pSegmentCollection.SegmentCount - 1
         Set pSegment = pSegmentCollection.Segment(i)
         Set pOutFeatureBuffer = pFeatureClass.CreateFeatureBuffer

         AddFields pOutFeatureBuffer, pFeature

         Set pPointCollection = New Polyline
         pPointCollection.AddPoint pSegment.FromPoint
         pPointCollection.AddPoint pSegment.ToPoint

         Set pOutFeatureBuffer.Shape = pPointCollection
         pOutFeatureCursor.InsertFeature pOutFeatureBuffer
      Next i

      pFeatureCursor.DeleteFeature
      
      Set pFeature = pFeatureCursor.NextFeature

      pOutFeatureCursor.Flush
    Next index

   pFeatureCursor.Flush

   'Refresh

   pMxDoc.ActiveView.Refresh
   
   MsgBox ("Completed!")
End Sub

5. The code above calls a routine called "AddFields". To support this, copy and paste this code so it follows the "End Sub" of the Click event handler above.

   Private Sub AddFields(pFeatureBuffer As IFeatureBuffer, pFeature As IFeature)
   'Copy the attributes from the original feature to the new one
   Dim pRowBuffer As IRowBuffer
   Dim pNewFields As IFields
   Dim pNewField As IField
   Dim pFields As IFields
   Dim pField As IField
   Dim i As Integer
   Dim NewFieldIndex As Long

   Set pRowBuffer = pFeatureBuffer
   Set pNewFields = pRowBuffer.Fields
   Set pFields = pFeature.Fields

   For i = 0 To pFields.FieldCount - 1
      Set pField = pFields.Field(i)

      If Not pField.Type = esriFieldTypeGeometry And Not pField.Type = esriFieldTypeOID And pField.Editable Then
        NewFieldIndex = pNewFields.FindField(pField.Name)

        If Not NewFieldIndex = -1 Then
           pFeatureBuffer.Value(NewFieldIndex) = pFeature.Value(i)
        End If
      End If
   Next
End Sub

6. In ArcMap, select the polyline layer whose features you want to split. Click the newly created button to split all the lines in this layer.