Query a point on a layer

Question

So I have a layer with contains points (yay)

I currently haveprivate function findAddressPoint(geom:Geometry):void {
 var q:Query = new Query();
 q.geometry = geom;
 q.spatialRelationship = Query.SPATIAL_REL_CONTAINS;
 q.returnGeometry = true;
 q.outFields = ["*"];

var task:QueryTask = new QueryTask();
 task.url = "http://svr-met-gisdev1:8399/arcgis/rest/services/M4/GIS_MasterMap/MapServer/1";
 task.execute(q, new AsyncResponder(onResult, onFail));
}

but no matter how acuratly i click i never get any results back, what am i doing wrong

it should be a point - point comparison (does geomA == geomB)

is there a nice quick easy way to add a 5px tolerance around the point thats clicked?

StevenColeman-Williams · Answer

Thank's guys
i managed to get buffered point working in the end 🙂

rscheitlin · Answer

Steven,

Or you could use a function like this to add pixels to the map point instead of map units:            private function createExtentAroundMapPoint(centerPoint:MapPoint, tolerance:Number):Extent
            {
                var screenPoint:Point = map.toScreen(centerPoint as MapPoint);
                
                var upperLeftScreenPoint:Point = new Point(screenPoint.x - tolerance, screenPoint.y - tolerance);
                var lowerRightScreenPoint:Point = new Point(screenPoint.x + tolerance, screenPoint.y + tolerance);
                
                var upperLeftMapPoint:MapPoint = map.toMap(upperLeftScreenPoint);
                var lowerRightMapPoint:MapPoint = map.toMap(lowerRightScreenPoint);
                
                return new Extent(upperLeftMapPoint.x, upperLeftMapPoint.y, lowerRightMapPoint.x, lowerRightMapPoint.y, map.spatialReference);
            }

kenbuja · Answer

Have you considered using IdentifyTask instead? IdentifyParameters contains a property for setting the tolerance in screen pixels.