我有2个故事板。我需要在它们之间切换。第一个故事板有一个地图视图控制器。当我切换到第二个故事板时,我改变了rootViewController,如下所示
let appDelegate = UIApplication.shared.delegate! as! AppDelegate
let storyboard = UIStoryboard(name: "LoginController", bundle: nil)
let viewController = storyboard.instantiateViewController(withIdentifier: "LoginController")
appDelegate.window?.rootViewController = viewController
appDelegate.window?.makeKeyAndVisible()
但是,当我打开第一个故事板时,我看到所有注释都是早先的。如何从地图中删除缓存?
因为mapviewController仍然存在,地图注释只是删除所有注释,然后在下面切换是必需的代码: -
for (int i =0; i < [mapView.annotations count]; i++) {
if ([[mapView.annotations objectAtIndex:i] isKindOfClass:[MyAnnotationClass class]]) {
[mapView removeAnnotation:[mapView.annotations objectAtIndex:i]];
}
}
只有在转换到第二个故事板的过程中删除注释,您才可以尝试
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
self.mapView.removeAnnotations(mapView.annotations)
}