在MKMapView中，用户看不到所有注释

我正在使用MKMapView并在地图上添加了许多注释引脚。 所有注释都属于不同的国家/地区，因此我无法将所有注释设置为对用户可见。

请尝试使用以下纬度和经度进行注释。

First annotation Latitude: 23.029690

First annotation Longitude: 72.527359

Second annotation Latitude: 34.210855

Second annotation Longitude: -118.622636

用于向mapview添加注释的代码。

 CLLocationCoordinate2D coordinate = CLLocationCoordinate2DMake([[dicObjects valueForKey:K_Latitude] doubleValue], [[dicObjects valueForKey:K_Longitude] doubleValue]); MyCustomAnnotation *myCustomAnnotation = [[MyCustomAnnotation alloc]initWithTitle:[NSString stringWithFormat:@"%@ ",[dicObjects valueForKey:K_Title]] Subtitle:[NSString stringWithFormat:@"%@",[dicObjects valueForKey:K_SubTitle]] andDescritpion:[NSString stringWithFormat:@"%@",[dicObjects valueForKey:K_TitelDes]] withLocation:coordinate andImageName:[dicObjects valueForKey:K_Rating] andTagValue:intTempCounter]; [mapViewPledgeList addAnnotation:myCustomAnnotation]; 

MyCustomAnnotation.h

 @interface MyCustomAnnotation : NSObject @property (nonatomic, readonly) CLLocationCoordinate2D coordinate; @property (copy, nonatomic) NSString *title; @property (copy, nonatomic) NSString *subTitle; @property (copy, nonatomic) NSString *titleDescritpion; @property (copy, nonatomic) NSString *strImageName; @property int intTagValue; - (id)initWithTitle:(NSString *)newTitle Subtitle:(NSString *)subTitle andDescritpion:(NSString *)titleDescritpion withLocation:(CLLocationCoordinate2D)location andTagValue:(int) intTag; - (MKAnnotationView *)annotationView; - (id)initWithTitle:(NSString *)newTitle Subtitle:(NSString *)subTitle andDescritpion:(NSString *)titleDescritpion withLocation:(CLLocationCoordinate2D)location andImageName:(NSString*) strImageName andTagValue:(int) intTag; @end 

MyCustomAnnotation.m

 #import "MyCustomAnnotation.h" @implementation MyCustomAnnotation #pragma mark - Custom Annotation View Setup - (MKAnnotationView *)annotationView{ MKAnnotationView *annotationView = [[MKAnnotationView alloc]initWithAnnotation:self reuseIdentifier:K_ID_CUSTOM_ANNOTATION]; annotationView.enabled = YES; annotationView.canShowCallout = YES; annotationView.image = kImage(_strImageName); UIButton *button = [UIButton buttonWithType:UIButtonTypeDetailDisclosure]; button.frame = CGRectMake(0, 0, 23, 23); button.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter; button.contentHorizontalAlignment = UIControlContentHorizontalAlignmentCenter; [button setImage:[[UIImage imageNamed:@"NextArrow"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal] forState:UIControlStateNormal]; annotationView.rightCalloutAccessoryView = button; return annotationView; } - (id)initWithTitle:(NSString *)newTitle Subtitle:(NSString *)subTitle andDescritpion:(NSString *)titleDescritpion withLocation:(CLLocationCoordinate2D)location andImageName:(NSString*) strImageName andTagValue:(int) intTag{ self = [super init]; if(self){ _title = newTitle; _subTitle = subTitle; _titleDescritpion = titleDescritpion; _coordinate = location; if ([strImageName intValue] == 1) { _strImageName = @"MapViewPinRed"; }else if([strImageName intValue] == 2){ _strImageName = @"MapViewPinOrange"; }else if ([strImageName intValue] == 3){ _strImageName = @"MapViewPinYellow"; }else if ([strImageName intValue] == 4){ _strImageName = @"MapViewPinLightGreen"; }else{ _strImageName = @"MapViewPinGreen"; } } return self; } @end 

我尝试下面的解决方案，但它没有工作。

1）使用MKMapRectUnion

  MKMapRect zoomRect = MKMapRectNull; for (id  annotation in mapViewPledgeList.annotations) { MKMapPoint annotationPoint = MKMapPointForCoordinate(annotation.coordinate); MKMapRect pointRect = MKMapRectMake(annotationPoint.x, annotationPoint.y, 0.1, 0.1); zoomRect = MKMapRectUnion(zoomRect, pointRect); } [mapViewPledgeList setVisibleMapRect:zoomRect animated:YES]; 

2）使用showAnnotations

  [mapViewPledgeList showAnnotations:mapViewPledgeList.annotations animated:YES]; 

问题： –建议任何解决方案，以便所有注释对用户可见。

Answer 1

不要忘记向地图添加注释。 也许这可能是问题所在

 [self.mapView addAnnotation:point]; 

Answer 2

您需要告诉mapView正确的MKCoordinateRegion类型的region值。 在告诉mapView显示正确的region之前，您需要进行一些计算。

A.通过遍历所有可用坐标数组找出以下变量的值。

 CLLocationDegrees minLatitude = // To be calculated CLLocationDegrees maxLatitude = // To be calculated CLLocationDegrees minLongitude = // To be calculated CLLocationDegrees maxLongitude = // To be calculated 

B.计算地图的中心坐标。

 CLLocationCoordinate2D center = CLLocationCoordinate2DMake((maxLatitude+minLatitude)/2, (maxLongitude+minLongitude)/2); 

C.计算latitudeDelta和longitudeDelta值 –

 CLLocationDegrees latitudeDelta = ABS(maxLatitude-minLatitude)*2; CLLocationDegrees longitudeDelta = ABS(maxLongitude-minLongitude)*2; 

D.计算span

 MKCoordinateSpan span = MKCoordinateSpanMake(latitudeDelta, longitudeDelta); 

E.计算region并告诉mapView显示 –

 MKCoordinateRegion region = MKCoordinateRegionMake(center, span); [mapView setRegion:region animated:YES]; 

在执行此操作时还有一些注意事项，例如您希望支持多少最大/最小latitudeDelta和longitudeDelta 。 在计算值时，可以将其应用于步骤C.

希望这可以帮助。

Answer 3

您需要通知mapview到完美区域，以便所有注释引脚都可见。

下面swift代码帮助你。

 extension MKMapView { func getAllAnnotationExpectCurrntLocation() -> [MKAnnotation] { var arrAnnotion: [MKAnnotation] = self.annotations arrAnnotion = arrAnnotion.filter { $0 !== self.userLocation } return arrAnnotion } func zoomToFitMapAnnotations() { guard self.annotations.count != 0 else { return } var topLeftCordinate = CLLocationCoordinate2D(latitude: -90, longitude: 180) var bottomRightCordinate = CLLocationCoordinate2D(latitude: 90, longitude: -180) for ann in self.getAllAnnotationExpectCurrntLocation() { topLeftCordinate.longitude = fmin(topLeftCordinate.longitude, ann.coordinate.longitude) topLeftCordinate.latitude = fmax(topLeftCordinate.latitude, ann.coordinate.latitude) bottomRightCordinate.longitude = fmax(bottomRightCordinate.longitude, ann.coordinate.longitude) bottomRightCordinate.latitude = fmin(bottomRightCordinate.latitude, ann.coordinate.latitude) } let latitude = topLeftCordinate.latitude - ((topLeftCordinate.latitude - bottomRightCordinate.latitude) * 0.5) let longitude = topLeftCordinate.longitude + ((bottomRightCordinate.longitude - topLeftCordinate.longitude) * 0.5) let latitudeDelta = fabs(topLeftCordinate.latitude - bottomRightCordinate.latitude) * 1.1 let longitudeDelta = fabs(bottomRightCordinate.longitude - topLeftCordinate.longitude) * 1.1 let span: MKCoordinateSpan = MKCoordinateSpan(latitudeDelta: latitudeDelta, longitudeDelta: longitudeDelta) let centerCordinate: CLLocationCoordinate2D = CLLocationCoordinate2D(latitude: latitude, longitude: longitude) let region: MKCoordinateRegion = MKCoordinateRegion(center: centerCordinate, span: span) let newregion = self.regionThatFits(region) self.setRegion(newregion, animated: true) } } 

Answer 4

Q]所有注释对用户都是可见的。

• 不幸的是，不可能将最小缩放级别设置为小于MKMapView最小限制。

• 另外在苹果官方地图应用程序下面的点是不可见的

  First annotation Latitude: 23.029690

  First annotation Longitude: 72.527359

  Second annotation Latitude: 34.210855

  Second annotation Longitude: -118.622636

注意：我们无法在最小限制后放大地图视图。