我希望能够在我的map注释上放置一个按钮和标签。带有标题、副标题和坐标的注释效果很好,但我无法显示按钮。funcdrawEvents(_loc:CLLocation,title1:String){mapView.delegate=self//letcenter=CLLocationCoordinate2D(latitude:loc.coordinate.latitude,longitude:loc.coordinate.longitude)letlat:CLLocationDegrees=center.latitudeletlong:CLLocationDegrees=center.l