我想计算用户和所有注释之间的距离。
我的注释来自一个解析的 csv 文件。我的注释在Location
课堂上。除了距离计算外,一切正常。
为了计算距离,我找到了这段代码:
-(void)mapView:(MKMapView *)mapView didUpdateUserLocation:(MKUserLocation *)newLocation
{
for (Location *annotation in self.mapView.annotations) {
CLLocationCoordinate2D coord = [annotation coordinate];
CLLocationCoordinate2D userCoordinate = [[[self.mapView userLocation] location] coordinate];
CLLocation *myLoc = [[CLLocation alloc] initWithLatitude:coord.latitude longitude:coord.longitude];
CLLocation *userLoc = [[CLLocation alloc] initWithLatitude:userCoordinate.latitude longitude:userCoordinate.longitude];
annotation.distance = [myLoc distanceFromLocation:userLoc];
NSLog(@"Distance is = %f", annotation.distance);
} // ! CRASH !
NSArray *sortedArray;
sortedArray = [self.mapView.annotations sortedArrayUsingComparator:^NSComparisonResult(id a, id b) {
NSNumber *first = [NSNumber numberWithDouble:[(Location*)a distance]];
NSNumber *second = [NSNumber numberWithDouble:[(Location*)b distance]];
return [first compare:second];
}];
但是我的应用程序在循环结束之前崩溃了。我发现,有断点,有一个奇怪的注释(MKUserLocation*
而不是Location*
);在此之后MKUserLocation*
,应用程序崩溃:
不正常(崩溃):
好的(没有崩溃):
为什么MKUserLocation
我的里面有self.mapView.annotations
?如何忽略它?
日志:
2014-09-22 06:01:47.965 MyFirstGPS2[472:60b] -[MKUserLocation setDistance:]: unrecognized selector sent to instance 0x9db0bb0
2014-09-22 06:01:48.030 MyFirstGPS2[472:60b] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[MKUserLocation setDistance:]: unrecognized selector sent to instance 0x9db0bb0'
*** First throw call stack:
(
0 CoreFoundation 0x01d971e4 __exceptionPreprocess + 180
1 libobjc.A.dylib 0x01b168e5 objc_exception_throw + 44
2 CoreFoundation 0x01e34243 -[NSObject(NSObject) doesNotRecognizeSelector:] + 275
3 CoreFoundation 0x01d8750b ___forwarding___ + 1019
4 CoreFoundation 0x01d870ee _CF_forwarding_prep_0 + 14
5 MyFirstGPS2 0x00005043 -[HPViewController mapView:didUpdateUserLocation:] + 1203
6 MapKit 0x006825e6 -[MKMapView(MKHeadingAdditions) _stopTrackingHeading] + 469
7 MapKit 0x00666a92 -[MKMapView _setUserTrackingMode:animated:fromTrackingButton:] + 301
8 MapKit 0x00666960 -[MKMapView setUserTrackingMode:animated:] + 56
9 MapKit 0x00682176 -[MKMapView(MKHeadingAdditions) disableHeadingTracking:] + 65
10 MapKit 0x00669524 -[MKMapView _didChangeRegionMidstream:] + 672
11 MapKit 0x00671fbd -[MKMapView mapLayerDidChangeVisibleRegion:] + 66
12 VectorKit 0x0407a15e -[VKMapView mapDidChangeVisibleRegion:] + 78
13 VectorKit 0x040821fe -[VKMapCanvas cameraControllerDidChangeCameraState:] + 46
14 VectorKit 0x0409f1f7 -[VKMapCameraController updatePanWithTranslation:] + 231
15 VectorKit 0x0408268f -[VKMapCanvas updatePanWithTranslation:] + 63
16 VectorKit 0x0407aca9 -[VKMapView updatePanWithTranslation:] + 73
17 MapKit 0x0069e30b -[MKMapGestureController handlePan:] + 530
18 UIKit 0x00b724f4 _UIGestureRecognizerSendActions + 230
19 UIKit 0x00b71168 -[UIGestureRecognizer _updateGestureWithEvent:buttonEvent:] + 383
20 UIKit 0x00b72bdd -[UIGestureRecognizer _delayedUpdateGesture] + 60
21 UIKit 0x00b7613d ___UIGestureRecognizerUpdate_block_invoke + 57
22 UIKit 0x00b760be _UIGestureRecognizerRemoveObjectsFromArrayAndApplyBlocks + 317
23 UIKit 0x00b6c7ac _UIGestureRecognizerUpdate + 199
24 UIKit 0x00817a5a -[UIWindow _sendGesturesForEvent:] + 1291
25 UIKit 0x00818971 -[UIWindow sendEvent:] + 1021
26 UIKit 0x007ea5f2 -[UIApplication sendEvent:] + 242
27 UIKit 0x007d4353 _UIApplicationHandleEventQueue + 11455
28 CoreFoundation 0x01d2077f __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 15
29 CoreFoundation 0x01d2010b __CFRunLoopDoSources0 + 235
30 CoreFoundation 0x01d3d1ae __CFRunLoopRun + 910
31 CoreFoundation 0x01d3c9d3 CFRunLoopRunSpecific + 467
32 CoreFoundation 0x01d3c7eb CFRunLoopRunInMode + 123
33 GraphicsServices 0x03acf5ee GSEventRunModal + 192
34 GraphicsServices 0x03acf42b GSEventRun + 104
35 UIKit 0x007d6f9b UIApplicationMain + 1225
36 MyFirstGPS2 0x00013592 main + 130
37 libdyld.dylib 0x0258a701 start + 1
38 ??? 0x00000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)
注意:我正在使用此页面中的代码来解析 csv 文件,我认为这不是问题:http: //blog.smartfrog.fr/post/32123941502/tutorial-ios-mapkit