osmdroid没有加载使用API​​的地图

Question

我试图拥有使用OpencyClemap的地图，但没有加载地图

 final String[] tileURLs = {"http://a.tile.thunderforest.com/cycle/",
                "http://b.tile.thunderforest.com/cycle/",
                "http://c.tile.thunderforest.com/cycle/"};

        final ITileSource OCM =
                new XYTileSource("Open Cycle Map",
                        0,
                        19,
                        512,
                        ".png?apikey=" + API_KEY,
                        tileURLs,
                        "from open cycle map");
        map = (MapView) findViewById(R.id.mapview);
        map.setTileSource(OCM);