public override bool HasZ {get; set;}

// list of points
List<MapPoint> points = new List<MapPoint>
{
  MapPointBuilderEx.CreateMapPoint(0, 0, 2, 3, 1),
  MapPointBuilderEx.CreateMapPoint(1, 1, 5, 6),
  MapPointBuilderEx.CreateMapPoint(2, 1, 6),
  MapPointBuilderEx.CreateMapPoint(0, 0)
};

// will have attributes because it is created with convenience method
Polyline polylineWithAttrs = PolylineBuilderEx.CreatePolyline(points);
bool hasZ = polylineWithAttrs.HasZ;          // hasZ = true
bool hasM = polylineWithAttrs.HasM;          // hasM = true
bool hasID = polylineWithAttrs.HasID;        // hasID = true

// will not have attributes because it is specified as a parameter
Polyline polylineWithoutAttrs = 
  PolylineBuilderEx.CreatePolyline(points, AttributeFlags.None);
hasZ = polylineWithoutAttrs.HasZ;          // hasZ = false
hasM = polylineWithoutAttrs.HasM;          // hasM = false
hasID = polylineWithoutAttrs.HasID;        // hasID = false

// will have attributes because it is created with convenience method
Polygon polygonWithAttrs = PolygonBuilderEx.CreatePolygon(points);
hasZ = polygonWithAttrs.HasZ;               // hasZ = true
hasM = polygonWithAttrs.HasM;               // hasM = true
hasID = polygonWithAttrs.HasID;             // hasID = true

// will not have attributes because it is specified as a parameter
Polygon polygonWithoutAttrs = 
      PolygonBuilderEx.CreatePolygon(points, AttributeFlags.None);
hasZ = polygonWithoutAttrs.HasZ;               // hasZ = false
hasM = polygonWithoutAttrs.HasM;               // hasM = false
hasID = polygonWithoutAttrs.HasID;             // hasID = false

// will not have attributes because it is specified as a parameter
PolylineBuilderEx polylineB = 
           new PolylineBuilderEx(points, AttributeFlags.None);
hasZ = polylineB.HasZ;                      // hasZ = false
hasM = polylineB.HasM;                      // hasM = false
hasID = polylineB.HasID;                    // hasID = false

// will have attributes because it is passed an attributed polyline
polylineB = new PolylineBuilderEx(polylineWithAttrs);
hasZ = polylineB.HasZ;                      // hasZ = true
hasM = polylineB.HasM;                      // hasM = true
hasID = polylineB.HasID;                    // hasID = true

// will not have attributes because it is passed a non-attributed polyline
polylineB = new PolylineBuilderEx(polylineWithoutAttrs);
hasZ = polylineB.HasZ;                      // hasZ = false
hasM = polylineB.HasM;                      // hasM = false
hasID = polylineB.HasID;                    // hasID = false

// will not have attributes because it is specified as a parameter
PolygonBuilderEx polygonB = new PolygonBuilderEx(points, AttributeFlags.None);
hasZ = polygonB.HasZ;                       // hasZ = false
hasM = polygonB.HasM;                       // hasM = false
hasID = polygonB.HasID;                     // hasID = false

// will have attributes because it is passed an attributed polygon
polygonB = new PolygonBuilderEx(polygonWithAttrs);
hasZ = polygonB.HasZ;                       // hasZ = true
hasM = polygonB.HasM;                       // hasM = true
hasID = polygonB.HasID;                     // hasID = true

// will not have attributes because it is passed a non-attributed polygon
polygonB = new PolygonBuilderEx(polygonWithoutAttrs);
hasZ = polygonB.HasZ;                       // hasZ = true
hasM = polygonB.HasM;                       // hasM = true
hasID = polygonB.HasID;                     // hasID = true

PolylineBuilderEx polylineBuilder = new PolylineBuilderEx(polyline);
polylineBuilder.HasZ = true;

// The HasZ property is set to true for all the points in
// polyline3D when you call ToGeometry().
Polyline polyline3D = polylineBuilder.ToGeometry();

// For this example, create Z-values. 
// You may want to pass them in as a parameter.
int numPoints = polyline3D.PointCount;
double[] zValues = new double[numPoints];
for (int i = 0; i < numPoints; i++)
{
  zValues[i] = i % 2 == 0 ? 2 : 1;
}

// We need to know at which point index each part starts
int partPointIndex = 0;  
int numParts = polyline3D.PartCount;

for (int i = 0; i < numParts; i++)
{
  var part = polyline3D.Parts[i];
  int numSegments = part.Count;

  for (int j = 0; j < numSegments; j++)
  {
    Segment segment = part[j];

    MapPointBuilderEx pointBuilder = new MapPointBuilderEx(segment.StartPoint);
    pointBuilder.Z = zValues[partPointIndex++];
    MapPoint startPoint = pointBuilder.ToGeometry();

    // Make sure that the end point of this segment is the same as the start point of the next segment
    pointBuilder = new MapPointBuilderEx(segment.EndPoint);
    pointBuilder.Z = zValues[partPointIndex];
    MapPoint endPoint = pointBuilder.ToGeometry();

    SegmentType segmentType = segment.SegmentType;
    SegmentBuilderEx segmentBuilder = null;
    switch (segmentType)
    {
      case SegmentType.Line:
        segmentBuilder = new LineBuilderEx((LineSegment)segment);
        break;
      case SegmentType.Bezier:
        segmentBuilder = new CubicBezierBuilderEx((CubicBezierSegment)segment);
        break;
      case SegmentType.EllipticArc:
        segmentBuilder = new EllipticArcBuilderEx((EllipticArcSegment)segment);
        break;
    }

    // Only change the start and end point which now have Z-values set. 
    // This will preserve the curve if the segment is an EllipticArcSegment or CubicBezierSegment.
    segmentBuilder.StartPoint = startPoint;
    segmentBuilder.EndPoint = endPoint;
    segment = segmentBuilder.ToSegment();

    polylineBuilder.ReplaceSegment(i, j, segment);
  }

  // Move point index for the next part
  partPointIndex++;
}

polyline3D = polylineBuilder.ToGeometry();
return polyline3D;