如何在OpenLayers 5中删除图形？

Question

I am using OpenLayers to create a map that allows a user to draw on it. The drawing options are implemented from the official docs and do work. https://openlayers.org/en/latest/examples/draw-features.html

I tried to give the user an option to delete his former drawing. By holding the key "A" you can see the users selection. Now this selected drawings should be deleted in the moment the key is released (but nothing happened).

var select = new Select();

window.addEventListener('keydown', function (event) {
    // A
    if (event.keyCode == 65) {
        map.addInteraction(select);
    }
});
window.addEventListener('keyup', function (event) {
    if (event.keyCode == 65) {
        var selectedFeatures = select.getFeatures();
        selectedFeatures.clear();
        map.removeInteraction(select);
    }
});

What am I missing?

Answer 1

Since i am missing the reputation to post a comment, i have to post this as answer. First, keyCode is deprecated , nowadays you should just use event.key , which also makes the code clearer for you, since the key is simply "a" .

The other problem is, you get the selected Features by select.getFeatures(), which either returns a Feature or a Collection (see API ). The Feature does not have a clear method, but you can get the layer, and then remove the selected feature from it's source. This could look something like this:

var selectSource = select.getLayer(selectedFeature).getSource();
selectSource.removeFeature(selectedFeature);

this is, assuming you select a single feature, otherwise you could loop over the selected features.