Get all features from the Openlayers 3 viewport

问题

I am trying to find out all the features which are visible (viewport) on a layer in Openlayers 3.

I am able to find out a single feature if I add a click event to the map which is as follows. But I am not able to find all the features which are visible in the viewport. Could anyone help with this?

map.on('click', function(evt) {
        var feature = map.forEachFeatureAtPixel(evt.pixel,
            function(feature, layer) {
                return feature;
            });
});

回答1:

I propose that first you get the extent of the view :

var extent = yourMap.getView().calculateExtent(yourMmap.getSize());

then get all features within this extent :

yourVectorSource.forEachFeatureInExtent(extent, function(feature){
    // do something 
}); 

来源：https://stackoverflow.com/questions/38785940/get-all-features-from-the-openlayers-3-viewport