Engine中如何为不含Z值的Polyline设置Z值？

【解决办法】：
1，首先获取不带Z值的IPolyline，遍历其Part，获取IPoint，将IPoint转为IZAware，设置其ZAware = true; 然后为点赋z值；
2，将新的Point重新构建成IPolyline，将该IPolyline转为IZAware，设置其ZAware = true 即可

注：IPolygon的方法与IPolyline一样， 将Path换为Ring即可。可参考下面代码：

private IPolyline addZValue(IPolyline polyline) 

{ 

if (polyline != null) 

{ 

IGeometryCollection geoCol = new PolylineClass(); 

IGeometryCollection geoColNew = new PolylineClass(); 

geoCol = polyline as IGeometryCollection; 



for (int i = 0; i < geoCol.GeometryCount; i++) 

{ 

IPointCollection pointCol = geoCol.get_Geometry(i) as IPointCollection; 

IPointCollection pointColNew = new PathClass(); 

for (int j = 0; j < pointCol.PointCount; j++) 

{ 

IPoint point = pointCol.get_Point(j); 

IZAware zAware = point as IZAware; 

zAware.ZAware = true; 

point.Z = 0; //Z值

pointColNew.AddPoint(point); 

} 

IPath path = pointColNew as IPath; 

geoColNew.AddGeometry(path as IGeometry); 

} 

IPolyline polylineNew = new PolylineClass(); 

polylineNew = geoColNew as IPolyline; 

IZAware zAwareNew = polylineNew as IZAware; 

zAwareNew.ZAware = true; 

return polylineNew; 

} 

else 

return null; 



}