MKUserTrackingBarButtonItem 在放大时崩溃

Question

我正在使用MKUserTrackingBarButtonItem来跟踪用户。使用用户跟踪栏按钮时，我无法设置缩放。所以我试着放大屏幕.并且应用程序在几个步骤后崩溃。我附近有一个坐标，我正在尝试使用它来跟踪用户相对于坐标。为什么应用程序崩溃。有没有更好的方法可以做到这一点？任何帮助将不胜感激。这是我的代码：-

 -(void) viewWillAppear:(BOOL)animated{
[super viewWillAppear:animated];
self.mapView.delegate = self;

_coordinate1.latitude = 29.9431438;
_coordinate1.longitude = -95.5170326;
 self.mapView.showsUserLocation = YES; }

-(void) viewDidAppear:(BOOL)animated{
[super viewDidAppear:animated];

  MKCoordinateRegion region = [self regionFromLocations:self.currentLoc];
[self displayPoints];
MKCoordinateRegion adjustRegion = [self.mapView regionThatFits:region];
self.mapView.autoresizingMask = (UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight);
[self.mapView setRegion:adjustRegion animated:YES]; }


- (void)viewDidLoad {
[super viewDidLoad];
 MKUserTrackingBarButtonItem *locateMeButton = [[MKUserTrackingBarButtonItem alloc] initWithMapView:self.mapView];

NSArray *toolbarItems = [NSArray arrayWithObjects: locateMeButton,
                         nil];
self.toolBar.items = toolbarItems; }


- (void)viewWillDisappear:(BOOL)animated {
NSLog(@"viewwillDisapear");
[self.mapView setUserTrackingMode:MKUserTrackingModeNone];
[super viewWillDisappear:animated];}

-(void)mapView:(MKMapView *)mapView didUpdateUserLocation:(MKUserLocation *)userLocation {
// getting current location
self.currentLoc = userLocation.location.coordinate;
NSLog(@"loc- %f   %f", self.currentLoc.longitude, self.currentLoc.latitude); }

Answer 1

通过在视图消失时删除地图视图来解决问题

-（void）viewWillDisappear：（BOOL）animated{

[super viewWillDisappear:animated];
self.mapView.delegate = nil;
[self.mapView removeFromSuperview];

}