topic Re: get the coordinates from a shapefile in Qt Maps SDK Questions

get the coordinates from a shapefile

TQGiser — Tue, 10 Oct 2023 09:21:39 GMT

Hi,all!

I made a ShapefileFeatureTable like this:

m_table1 = new ShapefileFeatureTable("E:/test/tp2.shp")(tp2 is a polyline shapefile);

i can use m_table1->extent().xMax() know the evelope's x,y coords;

but when i want to know the x,y coord of the point which explode by the polylineshapefile,

i dont know how to work with it,

Just like the function in ArcPy:

arcpy.da.SearchCursor(polyLineShapeFile, ['SHAPE@X', 'SHAPE@Y', 'SHAPE@M'], explode_to_points=True)

thans a lot!!

LucasDanzinger — Thu, 12 Oct 2023 16:19:33 GMT

First thing to do after creating the shapefile feature table is to query it for the feature you want, using the query parameters - https://developers.arcgis.com/qt/cpp/api-reference/esri-arcgisruntime-featuretable.html#queryFeatures

Once you get the geomtry, you'll need to use geometry_cast to cast the base class Geometry to a Polyline.

The Polyline is-a Multipart geometry. You'll want to go through the parts, and for-each part, you can get a list of the points/vertices that make up the part https://developers.arcgis.com/qt/cpp/api-reference/esri-arcgisruntime-immutablepart.html#points.

Hope this helps!

TQGiser — Mon, 16 Oct 2023 02:24:36 GMT

Thank you for the suggestion,but it do not work😂

In the api reference,the offical mathord is QFuture<*>:

and i tried like this:

the resault is：

seems like i have got the Geometry,

but the FeatureQueryResult has not function to get the geometry point list😂

so,what can i do

TQGiser — Mon, 16 Oct 2023 11:52:26 GMT

Hi,all,i have figure out!😀