topic How to use QueryParameters to get features contained in an area? in ArcGIS Runtime SDK for Android Questions

How to use QueryParameters to get features contained in an area?

GaelDurand — Sun, 12 Dec 2021 03:57:47 GMT

I would like to select features according to a QueryParameters object.

I don't understand why I get all features when I call queryFeaturesAsync whereas I expect a subset of it.

I tried in vain to change the value of SpatialRelationship, set an envelope or set max features.

Point gps = new Point(-1.640235, 48.127568, SpatialReferences.getWgs84());
final Polygon searchGeometry = GeometryEngine.buffer(gps, 500);

QueryParameters queryParams = new QueryParameters();
queryParams.setGeometry(searchGeometry);
queryParams.setMaxFeatures(500);
queryParams.setOutSpatialReference(SpatialReferences.getWgs84());
queryParams.setSpatialRelationship(QueryParameters.SpatialRelationship.CONTAINS);

final ListenableFuture<FeatureQueryResult> results = geoDbTable.queryFeaturesAsync(queryParams);

results.addDoneListener(new Runnable() {

 @Override public void run() {
 try {
 final FeatureQueryResult fqr = results.get();

 List result = new ArrayList();
 int counter = 0;
 while (fqr.iterator().hasNext()){
 counter+=1;
 if (counter%100 == 0) {
 Log.d("FeatureQueryResult", Long.toString(counter));
 }
 }
}
}

Re: How to use QueryParameters to get features contained in an area?

AlexanderNohe1 — Mon, 18 Sep 2017 12:57:10 GMT

I believe that your searchGeometry takes on the spatial reference of the point that you are buffering. Therefore, I believe you created a 500 degree buffer which will encompass the globe twice over. You may want to pick a different spatial reference to use like web mercator which is measured in meters.

Re: How to use QueryParameters to get features contained in an area?

GaelDurand — Sun, 12 Dec 2021 03:57:50 GMT

Hi Alexander,

I followed your advice by converting from WGS 84 to Web Mercator, but the result is the same.

It's as if queryParams was useless whichever Spatial Reference I chose.

Moreover, I got more than 500 features while this method should only return 500 features because of setMaxFeatures(500).

Do you see what's wrong with my code?

Point gps = new Point(-1.640235, 48.127568, SpatialReferences.getWgs84());
Point mercator = CoordinateFormatter.fromUtm(CoordinateFormatter.toUtm(gps, CoordinateFormatter.UtmConversionMode.LATITUDE_BAND_INDICATORS, true), 
                                             SpatialReferences.getWebMercator(), CoordinateFormatter.UtmConversionMode.LATITUDE_BAND_INDICATORS);

TextSymbol textSymbol =
    new TextSymbol(20, "Test", Color.rgb(255, 0, 0),
                  TextSymbol.HorizontalAlignment.CENTER, TextSymbol.VerticalAlignment.BOTTOM);
Graphic textGraphic = new Graphic(mercator, textSymbol);
mGraphicsOverlayETARE.getGraphics().add(textGraphic);

final Polygon searchGeometry = GeometryEngine.buffer(mercator, 500);

// create a query to find which features are contained by the query geometry
QueryParameters queryParams = new QueryParameters();
queryParams.setGeometry(searchGeometry);
queryParams.setMaxFeatures(500);
queryParams.setOutSpatialReference(SpatialReferences.getWebMercator());
queryParams.setSpatialRelationship(QueryParameters.SpatialRelationship.CONTAINS);

Re: How to use QueryParameters to get features contained in an area?

AlexanderNohe1 — Wed, 20 Sep 2017 13:27:40 GMT

Rather than doing the CoordinateFormatter class, I would encourage you to use GeometryEngine::Project(). This will project the point to the correct spatial reference which you can then pass in (might be a little more straightforward than what you have there). When doing this, are you seeing different results?

Where are you executing this query? Can we see that line of code?