topic Re: iOS Buffer and Spatial Selection in ArcGIS Runtime SDK for iOS Questions

iOS Buffer and Spatial Selection

DarrenMackiewicz — Tue, 27 Sep 2011 23:59:44 GMT

Can the #Esri iOS API do a buffer on a polygon feature or graphics point - and spatially select the polygon features that the buffer intersects? (Like a traditional Buffer in GIS).

So, not just return a graphic of a distance around a point - Can it actually do the spatial selection ?

Re: iOS Buffer and Spatial Selection

NimeshJarecha — Wed, 28 Sep 2011 03:21:30 GMT

Use AGSGeometryEngine methods.

Regards,
Nimesh

Re: iOS Buffer and Spatial Selection

DarrenMackiewicz — Wed, 28 Sep 2011 14:27:21 GMT

Thanks Nimesh

I tried that - I used -bufferGeometry:byDistance:

That still only returned a polygon.
I want to take that polygon and find the parcels below it that it intersects.
Am I on the right path?

Re: iOS Buffer and Spatial Selection

DarrenMackiewicz — Wed, 28 Sep 2011 15:32:31 GMT

Answered my own question.

After getting the buffer geometry, run a spatial selection using a querytask :
mPolygon is the geometry of the buffer I already did.

        //set up query task against layer, specify the delegate
        self.queryTask = [AGSQueryTask queryTaskWithURL:[NSURL URLWithString:countiesLayerURL]];
        self.queryTask.delegate = self;


        self.query = [AGSQuery query];
        self.query.outFields = [NSArray arrayWithObjects:@"*", nil];
        self.query.returnGeometry = YES;
        self.query.geometry = mPolygon;
        self.query.spatialRelationship = AGSSpatialRelationshipIntersects;
        [self.queryTask executeWithQuery:self.query];

Re: iOS Buffer and Spatial Selection

NimeshJarecha — Thu, 29 Sep 2011 18:35:34 GMT

Good to know 🙂