Split a polyline at the vertices using ArcObjects

Summary

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

Procedure

1. Start ArcMap.
2. Create a new UIButtonControl.
   
3. Right-click the UIButtonControl and select View Source.
4. Copy and paste the following code into the UIButtonControl's click event.
   
   
   Private Sub Command3_Click()Sub Command3_Click()
      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()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.