ArcGIS添加瓦片图层以后不显示

新建一个xcode工程，在AGSMapView *mapView上面添加一个瓦片图层

运行以后瓦片不显示，我竟然犯了一个弱智的问题，没有设定范围

 double xmin, ymin, xmax, ymax;
    xmin = 472264.427929907;
    ymin = 3472819.05219064;
    xmax = 539049.628166974;
    ymax = 3539604.25242771;
    
    AGSEnvelope *env = [AGSEnvelope envelopeWithXmin:xmin ymin:ymin xmax:xmax ymax:ymax spatialReference:nil];
    [_mapView zoomToEnvelope:env animated:YES

];