问题描述
我有一个地图视图,其中注释的坐标不断更新,但是当我使用 setCoordinate 时,注释不会移动.如何刷新注释以反映它们的坐标?
I have a mapview where the annotation's coordinates are constantly being updated but when I use setCoordinate, the annotation does not move. How do I refresh the annotations to reflect their coordinates?
- (void)updateUnits { PFQuery *query = [PFQuery queryWithClassName:@"devices"]; [query whereKeyExists:@"location"]; [query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) { if (!error) { for (PFObject *row in objects) { PFGeoPoint *geoPoint = [row objectForKey:@"location"]; CLLocationCoordinate2D coord = { geoPoint.latitude, geoPoint.longitude }; for (id<MKAnnotation> ann in mapView.annotations) { if ([ann.title isEqualToString:[row objectForKey:@"deviceid"]]) { [ann setCoordinate:coord]; NSLog(@"latitude is: %f" , coord.latitude); NSLog(@"Is called"); break; } else { //[self.mapView removeAnnotation:ann]; } } } } else { } }]; }
推荐答案
更新(反映解决方案):
Updated (to reflect the solution):
拥有自己的自定义注释并实现 setCoordinate 和/或合成坐标可能会导致问题.
Having your own custom annotations and implementing setCoordinate and/or synthesizing coordinate may cause issues.
来源:http://developer.apple.com/库/ios/#documentation/UserExperience/Conceptual/LocationAwarenessPG/AnnotatingMaps/AnnotatingMaps.html
以前的解决方案:
您可以简单地删除所有注释,然后重新添加它们.
You can simply remove all of the annotations and then re-add them.
[mapView removeAnnotations:[mapView.annotations]]; [mapView addAnnotations:(NSArray *)];
或删除它们并一一重新添加:
or remove them and re-add them one by one:
for (id<MKAnnotation> annotation in mapView.annotations) { [mapView removeAnnotation:annotation]; // change coordinates etc [mapView addAnnotation:annotation]; }