For example:
extent := GisNoWorld ;
shp := ll.FindFirst( extent, 'ID=1' )
if Assigned( shp ) then begin
extent := GisMaxExtent( extent, shp.ProjectedExtent ) ;
GIS.VisibleExtent := extent ;
GIS.Zoom := GIS.Zoom / 2 ;
end ;
Note:
TGIS_Shape.Extent and TGIS_Shape.ProjectedExtent are similar. The main difference between them is the first provides extent in the layer coordinate system, whereas the second provides extent already in the viewer coordinate system.