Question

我正在使用MKMapView并在地图中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

为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<MKAnnotation>

@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

我尝试了以下解决方案，但它无效。

1）使用MKMapRectUnion

 MKMapRect zoomRect = MKMapRectNull;
    for (id <MKAnnotation> 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都可见。

Answer 1

不要忘记向地图添加注释。也许这可能是问题

[self.mapView addAnnotation:point];

Answer 2

您需要告诉mapView region类型为MKCoordinateRegion的正确值。您需要先进行一些计算，然后才能告诉mapView显示正确的region。

一个。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中。计算地图的中心坐标。

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

℃。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);

电子。计算region并告诉您的mapView显示此内容 -

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

在执行此操作时还需要考虑一些因素，例如您希望支持的最大/分钟latitudeDelta和longitudeDelta。在计算值时，这可以应用于步骤C.

希望这有帮助。

Answer 3

您需要将mapview告知完美区域，以便所有注释引脚都可见。

下面的swift代码可以帮助你。

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，无法将最小缩放级别设置为低于MKMapView最低限制。
同样在苹果官方地图应用程序中，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：我们无法在地图视图达到最低限制后放大。

在MKMapView中，用户看不到所有注释

4 个答案: