Polygon delete and coordinates relete.

FNC TMS FNC Maps
1

I would like to remove a polygon from polygon collection. Can I use DeleteAt method to do that? Do I need to call dispose() first before I delete the polygon?
If I delete a polygon by its index, is the polygon collection size automatically changed and all remaining polygon index will be re-caculated?
The same question applied to coordinates. I am using C++ builder and would like to find the efficient and safe way to delete polygons and coordiantes.
Thanks!

2

Hi,

You can use both Delete or Destroy to remove Polygons from the map and from the Polygons collection.

Example:

  TMSFNCMaps1.Polylines[Index].Destroy;
//or
  TMSFNCMaps1.Polylines.Delete(Index);

To remove specific coordinates from a Polygon, you can use the Destroy call in combination with Recreate and BeginUpdate/EndUpdate.

Example:

    TMSFNCMaps1.BeginUpdate;
    TMSFNCMaps1.Polylines[Index].Coordinates[Index].Destroy;
    TMSFNCMaps1.Polylines[Index].Recreate := True;
    TMSFNCMaps1.EndUpdate;
3

Hi,
Thanks for the quick reply!
When I use destroy or delete method to remove a polygon from a polygon collection, does that method free memory for me?
After the polygon/coordinate is removed, will the index of remaining polygon/coordinates re-calculated since the collection size reduces?
Thanks again!

4

Utilizing the Destroy method will remove the Polygon/Coordinate from the collection, and the indexes will be updated accordingly. This process should also free up the associated memory.

5

This doesn't seem to work. I had to use Delete(index) instead of using Destroy.