Question

我想要添加到我的MKMapView中的几个注释（它可以是0-n项，其中n通常大约为5）。我可以添加注释，但我想调整地图大小以适应屏幕上的所有注释，我不知道如何做到这一点。

我一直在关注-regionThatFits:，但我不太清楚如何处理它。我会发布一些代码来展示我到目前为止所拥有的内容。我认为这应该是一项普遍直截了当的任务，但到目前为止我对MapKit感到有些不知所措。

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation{

location = newLocation.coordinate;
//One location is obtained.. just zoom to that location

MKCoordinateRegion region;
region.center = location;

//Set Zoom level using Span
MKCoordinateSpan span;
span.latitudeDelta = 0.015;
span.longitudeDelta = 0.015;
region.span = span;
// Set the region here... but I want this to be a dynamic size
// Obviously this should be set after I've added my annotations
[mapView setRegion:region animated:YES];

// Test data, using these as annotations for now
NSArray *arr = [NSArray arrayWithObjects:@"one", @"two", @"three", @"four", nil];
float ex = 0.01;
for (NSString *s in arr) {
    JBAnnotation *placemark = [[JBAnnotation alloc] initWithLat:(location.latitude + ex) lon:location.longitude];
    [mapView addAnnotation:placemark];
    ex = ex + 0.005;
}
    // What do I do here?
    [mapView setRegion:[mapView regionThatFits:region] animated:YES];
}

请注意，这一切都发生在我收到位置更新时...我不知道这是否适合这样做。如果没有，哪里会更好？ -viewDidLoad？

提前致谢。

Answer 1

Jim发布的link已经死了，但我能够找到代码（我已经在某个地方添加了书签）。希望这会有所帮助。

- (void)zoomToFitMapAnnotations:(MKMapView *)mapView { 
    if ([mapView.annotations count] == 0) return; 

    CLLocationCoordinate2D topLeftCoord; 
    topLeftCoord.latitude = -90; 
    topLeftCoord.longitude = 180; 

    CLLocationCoordinate2D bottomRightCoord; 
    bottomRightCoord.latitude = 90; 
    bottomRightCoord.longitude = -180; 

    for(id<MKAnnotation> annotation in mapView.annotations) { 
        topLeftCoord.longitude = fmin(topLeftCoord.longitude, annotation.coordinate.longitude); 
        topLeftCoord.latitude = fmax(topLeftCoord.latitude, annotation.coordinate.latitude); 
        bottomRightCoord.longitude = fmax(bottomRightCoord.longitude, annotation.coordinate.longitude); 
        bottomRightCoord.latitude = fmin(bottomRightCoord.latitude, annotation.coordinate.latitude); 
    } 

    MKCoordinateRegion region; 
    region.center.latitude = topLeftCoord.latitude - (topLeftCoord.latitude - bottomRightCoord.latitude) * 0.5; 
    region.center.longitude = topLeftCoord.longitude + (bottomRightCoord.longitude - topLeftCoord.longitude) * 0.5;      

    // Add a little extra space on the sides
    region.span.latitudeDelta = fabs(topLeftCoord.latitude - bottomRightCoord.latitude) * 1.1;
    region.span.longitudeDelta = fabs(bottomRightCoord.longitude - topLeftCoord.longitude) * 1.1; 

    region = [mapView regionThatFits:region]; 
    [mapView setRegion:region animated:YES]; 
}

Answer 2

为什么这么复杂？

MKCoordinateRegion coordinateRegionForCoordinates(CLLocationCoordinate2D *coords, NSUInteger coordCount) {
    MKMapRect r = MKMapRectNull;
    for (NSUInteger i=0; i < coordCount; ++i) {
        MKMapPoint p = MKMapPointForCoordinate(coords[i]);
        r = MKMapRectUnion(r, MKMapRectMake(p.x, p.y, 0, 0));
    }
    return MKCoordinateRegionForMapRect(r);
}

Answer 3

我做了类似的事情来缩小（或缩小）包含点注释和当前位置的区域。您可以通过循环注释来扩展它。

基本步骤是：

计算最小纬度/长度
计算最大纬度/长度
为这两个点创建CLLocation对象
计算点之间的距离
使用中心点创建区域在点和距离之间转换到度
将区域传递到MapView以进行调整
使用调整后的区域设置MapView区域

    -(IBAction)zoomOut:(id)sender {

        CLLocationCoordinate2D southWest = _newLocation.coordinate;
        CLLocationCoordinate2D northEast = southWest;

        southWest.latitude = MIN(southWest.latitude, _annotation.coordinate.latitude);
        southWest.longitude = MIN(southWest.longitude, _annotation.coordinate.longitude);

        northEast.latitude = MAX(northEast.latitude, _annotation.coordinate.latitude);
        northEast.longitude = MAX(northEast.longitude, _annotation.coordinate.longitude);

        CLLocation *locSouthWest = [[CLLocation alloc] initWithLatitude:southWest.latitude longitude:southWest.longitude];
        CLLocation *locNorthEast = [[CLLocation alloc] initWithLatitude:northEast.latitude longitude:northEast.longitude];

        // This is a diag distance (if you wanted tighter you could do NE-NW or NE-SE)
        CLLocationDistance meters = [locSouthWest getDistanceFrom:locNorthEast];

        MKCoordinateRegion region;
        region.center.latitude = (southWest.latitude + northEast.latitude) / 2.0;
        region.center.longitude = (southWest.longitude + northEast.longitude) / 2.0;
        region.span.latitudeDelta = meters / 111319.5;
        region.span.longitudeDelta = 0.0;

        _savedRegion = [_mapView regionThatFits:region];
        [_mapView setRegion:_savedRegion animated:YES];

        [locSouthWest release];
        [locNorthEast release];
    }

Answer 4

从iOS7开始，您可以使用showAnnotations:animated:

[mapView showAnnotations:annotations animated:YES];

Answer 5

我有一个不同的答案。我本来打算实现缩放到适合算法，但我认为Apple 必须有办法在没有太多工作的情况下做我们想要的事情。使用API doco很快就表明我可以使用MKPolygon来做所需的事情：

/* this simply adds a single pin and zooms in on it nicely */
- (void) zoomToAnnotation:(MapAnnotation*)annotation {
    MKCoordinateSpan span = {0.027, 0.027};
    MKCoordinateRegion region = {[annotation coordinate], span};
    [mapView setRegion:region animated:YES];
}

/* This returns a rectangle bounding all of the pins within the supplied
   array */
- (MKMapRect) getMapRectUsingAnnotations:(NSArray*)theAnnotations {
    MKMapPoint points[[theAnnotations count]];

    for (int i = 0; i < [theAnnotations count]; i++) {
        MapAnnotation *annotation = [theAnnotations objectAtIndex:i];
        points[i] = MKMapPointForCoordinate(annotation.coordinate);
    }

    MKPolygon *poly = [MKPolygon polygonWithPoints:points count:[theAnnotations count]];

    return [poly boundingMapRect];
}

/* this adds the provided annotation to the mapview object, zooming 
   as appropriate */
- (void) addMapAnnotationToMapView:(MapAnnotation*)annotation {
    if ([annotations count] == 1) {
        // If there is only one annotation then zoom into it.
        [self zoomToAnnotation:annotation];
    } else {
        // If there are several, then the default behaviour is to show all of them
        //
        MKCoordinateRegion region = MKCoordinateRegionForMapRect([self getMapRectUsingAnnotations:annotations]);

        if (region.span.latitudeDelta < 0.027) {
            region.span.latitudeDelta = 0.027;
        }

        if (region.span.longitudeDelta < 0.027) {
            region.span.longitudeDelta = 0.027;
        }
        [mapView setRegion:region];
    }

    [mapView addAnnotation:annotation];
    [mapView selectAnnotation:annotation animated:YES];
}

希望这有帮助。

Answer 6

你也可以这样做..

// Position the map so that all overlays and annotations are visible on screen.
MKMapRect regionToDisplay = [self mapRectForAnnotations:annotationsToDisplay];
if (!MKMapRectIsNull(regionToDisplay)) myMapView.visibleMapRect = regionToDisplay;

- (MKMapRect) mapRectForAnnotations:(NSArray*)annotationsArray
{
    MKMapRect mapRect = MKMapRectNull;

    //annotations is an array with all the annotations I want to display on the map
    for (id<MKAnnotation> annotation in annotations) { 

        MKMapPoint annotationPoint = MKMapPointForCoordinate(annotation.coordinate);
        MKMapRect pointRect = MKMapRectMake(annotationPoint.x, annotationPoint.y, 0, 0);

        if (MKMapRectIsNull(mapRect)) 
        {
            mapRect = pointRect;
        } else 
        {
            mapRect = MKMapRectUnion(mapRect, pointRect);
        }
    }

     return mapRect;
}

Answer 7

根据每个人的信息和建议，我想出了以下内容。感谢大家参与本次讨论会的贡献:)这将包含在包含mapView的视图控制器中。

- (void)zoomToFitMapAnnotations { 

if ([self.mapView.annotations count] == 0) return; 

int i = 0;
MKMapPoint points[[self.mapView.annotations count]];

//build array of annotation points
for (id<MKAnnotation> annotation in [self.mapView annotations])
        points[i++] = MKMapPointForCoordinate(annotation.coordinate);

MKPolygon *poly = [MKPolygon polygonWithPoints:points count:i];

[self.mapView setRegion:MKCoordinateRegionForMapRect([poly boundingMapRect]) animated:YES]; 
}

Answer 8

就我而言，我开始使用CLLocation对象并为每个对象创建注释我只需要放置两个注释，所以我有一个简单的方法来构建点数组，但是可以很容易地扩展它以构建一个给定一组CLLocations的任意长度的数组。

这是我的实现（不需要创建MKMapPoints）：

//start with a couple of locations
CLLocation *storeLocation = store.address.location.clLocation;
CLLocation *userLocation = [LBLocationController sharedController].currentLocation;

//build an array of points however you want
CLLocationCoordinate2D points[2] = {storeLocation.coordinate, userLocation.coordinate};

//the magic part
MKPolygon *poly = [MKPolygon polygonWithCoordinates:points count:2];
[self.mapView setRegion:MKCoordinateRegionForMapRect([poly boundingMapRect])];

Answer 9

使用Swift，多边形和一些额外的填充，我使用了以下内容：

func zoomToFit() {
    var allLocations:[CLLocationCoordinate2D] = [
        CLLocationCoordinate2D(latitude: 32.768805, longitude: -117.167119),
        CLLocationCoordinate2D(latitude: 32.770480, longitude: -117.148385),
        CLLocationCoordinate2D(latitude: 32.869675, longitude: -117.212929)
    ]

    var poly:MKPolygon = MKPolygon(coordinates: &allLocations, count: allLocations.count)

    self.mapView.setVisibleMapRect(poly.boundingMapRect, edgePadding: UIEdgeInsetsMake(40.0, 40.0, 40.0, 40.0), animated: false)
}

Answer 10

MKMapView＆＃39;中有一种新方法。从iOS 7开始，你可以使用

声明

SWIFT
func showAnnotations(_ annotations: [AnyObject]!,
            animated animated: Bool)
目标-C
- (void)showAnnotations:(NSArray *)annotations
               animated:(BOOL)animated
参数

注释您希望在其中可见的注释   地图。如果您希望更改地图区域，则为“是”   动画，或者如果您希望地图显示新区域，则为NO   立即没有动画。

讨论

调用此方法更新   region属性中的值以及可能的其他属性   反映新的地图区域。

Answer 11

这是Mustafa的答案中的SWIFT等效（确认工作于：Xcode6.1，SDK 8.2）：

func zoomToFitMapAnnotations() {
    if self.annotations.count == 0 {return}

    var topLeftCoordinate = CLLocationCoordinate2D(latitude: -90, longitude: 180)
    var bottomRightCoordinate = CLLocationCoordinate2D(latitude: 90, longitude: -180)

    for object in self.annotations {
        if let annotation = object as? MKAnnotation {
            topLeftCoordinate.longitude = fmin(topLeftCoordinate.longitude, annotation.coordinate.longitude)
            topLeftCoordinate.latitude = fmax(topLeftCoordinate.latitude, annotation.coordinate.latitude)
            bottomRightCoordinate.longitude = fmax(bottomRightCoordinate.longitude, annotation.coordinate.longitude)
            bottomRightCoordinate.latitude = fmin(bottomRightCoordinate.latitude, annotation.coordinate.latitude)
        }
    }

    let center = CLLocationCoordinate2D(latitude: topLeftCoordinate.latitude - (topLeftCoordinate.latitude - bottomRightCoordinate.latitude) * 0.5, longitude: topLeftCoordinate.longitude - (topLeftCoordinate.longitude - bottomRightCoordinate.longitude) * 0.5)

    print("\ncenter:\(center.latitude) \(center.longitude)")
    // Add a little extra space on the sides
    let span = MKCoordinateSpanMake(fabs(topLeftCoordinate.latitude - bottomRightCoordinate.latitude) * 1.01, fabs(bottomRightCoordinate.longitude - topLeftCoordinate.longitude) * 1.01)
    print("\nspan:\(span.latitudeDelta) \(span.longitudeDelta)")

    var region = MKCoordinateRegion(center: center, span: span)


    region = self.regionThatFits(region)

    self.setRegion(region, animated: true)

}

Answer 12

一种可能的解决方案可能是测量当前位置与所有注释之间的距离，并使用MKCoordinateRegionMakeWithDistance方法创建距离比最远注释略大的区域。

虽然你添加的注释越多，这当然会越慢。

Answer 13

我知道这是一个老问题但是，如果你想在地图上显示ALREADY的所有注释，请使用：

 mapView.showAnnotations(mapView.annotations, animated: true)

Answer 14

基于me2（现在在Swift中）的优秀答案

func coordinateRegionForCoordinates(coords: [CLLocationCoordinate2D]) -> MKCoordinateRegion {
    var rect: MKMapRect = MKMapRectNull
    for coord in coords {
        let point: MKMapPoint = MKMapPointForCoordinate(coord)
        rect = MKMapRectUnion(rect, MKMapRectMake(point.x, point.y, 0, 0))
    }
    return MKCoordinateRegionForMapRect(rect)
}

Answer 15

- (void)zoomToFitMapAnnotations {

if ([self.mapview.annotations count] == 0) return;

int i = 0;
MKMapPoint points[[self.mapview.annotations count]];

//build array of annotation points
for (id<MKAnnotation> annotation in [self.mapview annotations])
    points[i++] = MKMapPointForCoordinate(annotation.coordinate);

MKPolygon *poly = [MKPolygon polygonWithPoints:points count:i];

[self.mapview setRegion:MKCoordinateRegionForMapRect([poly boundingMapRect]) animated:YES];
}

Answer 16

在斯特凡·卢卡的答案中添加其他内容。在这里，我们可以保留UserLocation以及自定义注释以适合MKMapView

 private func centerViewOnUserLocation() {
    
    if selectedLatitudeFromPreviousVC?.description != nil && selectedLongitudeFromPreviousVC?.description != nil {
        
        if let location = locationManager.location?.coordinate {
            let region = regionFor(coordinates: [
                CLLocationCoordinate2D(latitude: selectedLatitudeFromPreviousVC!, longitude: selectedLongitudeFromPreviousVC!),
                location])
            mkmapView.setRegion(region, animated: true)
        }
    } else {
        if let location = locationManager.location?.coordinate {
            let region = MKCoordinateRegion.init(center: location, latitudinalMeters: regionInMeters, longitudinalMeters: regionInMeters)
            mkmapView.setRegion(region, animated: true)
        }
    }
}

private func regionFor(coordinates coords: [CLLocationCoordinate2D]) -> MKCoordinateRegion {
    var r = MKMapRect.null

    for i in 0 ..< coords.count {
        let p = MKMapPoint(coords[i])
        r = r.union(MKMapRect(x: p.x, y: p.y, width: 0, height: 0))
    }

    var coordinateRegion = MKCoordinateRegion(r)
    coordinateRegion.span.latitudeDelta *= 1.5
    coordinateRegion.span.longitudeDelta *= 1.5
    return coordinateRegion
}

Answer 17

添加了一个if子句来处理1个位置 - 添加到mustufa的cound代码片段中。使用了pkclSoft的zoomToAnnotation函数：

if ([mapView.annotations count] == 1){
    MKCoordinateSpan span = {0.027, 0.027};
    region.span = span;
    CLLocationCoordinate2D singleCoordinate = [[mapView.annotations objectAtIndex:0] coordinate];
    region.center.latitude = singleCoordinate.latitude;
    region.center.longitude = singleCoordinate.longitude;
}
else
{
    // mustufa's code
}

Answer 18

由于我无法对答案发表评论，我想在@ me2的答案中添加一些便利（因为我认为这是最优雅的方法）。

对于我的个人项目，我只是在MKMapView类中添加了一个类别来封装＆＃34;可见区域＆＃34; ver常用操作的功能：设置为能够在MKMapView实例上查看所有当前加载的注释。结果是：

.h文件

#import <MapKit/MapKit.h>

@interface MKMapView (Extensions)

-(void)ij_setVisibleRectToFitAllLoadedAnnotationsAnimated:(BOOL)animated;
-(void)ij_setVisibleRectToFitAnnotations:(NSArray *)annotations animated:(BOOL)animated;


@end

.m文件

#import "MKMapView+Extensions.h"

@implementation MKMapView (Extensions)

/**
 *  Changes the currently visible portion of the map to a region that best fits all the currently loadded annotations on the map, and it optionally animates the change.
 *
 *  @param animated is the change should be perfomed with an animation.
 */
-(void)ij_setVisibleRectToFitAllLoadedAnnotationsAnimated:(BOOL)animated
{
    MKMapView * mapView = self;

    NSArray * annotations = mapView.annotations;

    [self ij_setVisibleRectToFitAnnotations:annotations animated:animated];

}


/**
 *  Changes the currently visible portion of the map to a region that best fits the provided annotations array, and it optionally animates the change.
    All elements from the array must conform to the <MKAnnotation> protocol in order to fetch the coordinates to compute the visible region of the map.
 *
 *  @param annotations an array of elements conforming to the <MKAnnotation> protocol, holding the locations for which the visible portion of the map will be set.
 *  @param animated    wether or not the change should be perfomed with an animation.
 */
-(void)ij_setVisibleRectToFitAnnotations:(NSArray *)annotations animated:(BOOL)animated
{
    MKMapView * mapView = self;

    MKMapRect r = MKMapRectNull;
    for (id<MKAnnotation> a in annotations) {
        ZAssert([a conformsToProtocol:@protocol(MKAnnotation)], @"ERROR: All elements of the array MUST conform to the MKAnnotation protocol. Element (%@) did not fulfill this requirement", a);
        MKMapPoint p = MKMapPointForCoordinate(a.coordinate);
        //MKMapRectUnion performs the union between 2 rects, returning a bigger rect containing both (or just one if the other is null). here we do it for rects without a size (points)
        r = MKMapRectUnion(r, MKMapRectMake(p.x, p.y, 0, 0));
    }

    [mapView setVisibleMapRect:r animated:animated];

}

@end

如您所见，到目前为止，我已添加了两种方法：一种用于将地图的可见区域设置为适合MKMapView实例上所有当前加载的注释的方法，另一种方法将其设置为任何对象数组。因此，要设置mapView的可见区域，代码将如下所示：

   //the mapView instance  
    [self.mapView ij_setVisibleRectToFitAllLoadedAnnotationsAnimated:animated];

我希望它有帮助=）

Answer 19

基于me2响应我为MKMapView写了一个类别来添加一些边距并跳过用户位置注释：

@interface MKMapView (ZoomToFitAnnotations)
- (void)zoomToFitAnnotations:(BOOL)animated;
@end

@implementation MKMapView (ZoomToFitAnnotations)
- (void)zoomToFitAnnotations:(BOOL)animated {
    if (self.annotations.count == 0)
        return;

    MKMapRect rect = MKMapRectNull;
    for (id<MKAnnotation> annotation in self.annotations) {
        if ([annotation isKindOfClass:[MKUserLocation class]] == false) {
            MKMapPoint point = MKMapPointForCoordinate(annotation.coordinate);
            rect = MKMapRectUnion(rect, MKMapRectMake(point.x, point.y, 0, 0));
        }
    }

    MKCoordinateRegion region = MKCoordinateRegionForMapRect(rect);
    region.span.longitudeDelta *= 2; // Margin
    region.span.latitudeDelta *= 2; // Margin
    [self setRegion:region animated:animated];
}
@end

Answer 20

CLLocationCoordinate2D min = CLLocationCoordinate2DMake(99999.0, 99999.0);
CLLocationCoordinate2D max = CLLocationCoordinate2DMake(-99999.0, -99999.0);

// find max/min....

// zoom to cover area
// TODO: Maybe better using a MKPolygon which can calculate its own fitting region.
CLLocationCoordinate2D center = CLLocationCoordinate2DMake((max.latitude + min.latitude) / 2.0, (max.longitude + min.longitude) / 2.0);
MKCoordinateSpan span = MKCoordinateSpanMake(max.latitude - min.latitude, max.longitude - min.longitude);
MKCoordinateRegion region = MKCoordinateRegionMake(center, span);

[_mapView setRegion:[_mapView regionThatFits:region] animated:YES];

Answer 21

此代码适用于我，它显示了当前位置的所有引脚，希望这对您有帮助，

func setCenterForMap() {
    var mapRect: MKMapRect = MKMapRectNull
    for loc in mapView.annotations {
        let point: MKMapPoint = MKMapPointForCoordinate(loc.coordinate)
        print( "location is : \(loc.coordinate)");
        mapRect = MKMapRectUnion(mapRect, MKMapRectMake(point.x,point.y,0,0))
    }
    if (locationManager.location != nil) {
        let point: MKMapPoint = MKMapPointForCoordinate(locationManager.location!.coordinate)
        print( "Cur location is : \(locationManager.location!.coordinate)");
        mapRect = MKMapRectUnion(mapRect, MKMapRectMake(point.x,point.y,0,0))
    }

    mapView.setVisibleMapRect(mapRect, edgePadding: UIEdgeInsetsMake(40.0, 40.0, 40.0, 40.0), animated: true)

}

Answer 22

我希望这至少是相关的，这是我为Mono（基于pkclSoft的答案）整理的内容：

void ZoomMap (MKMapView map)
{
    var annotations = map.Annotations;

    if (annotations == null || annotations.Length == 0) 
        return;

    var points = annotations.OfType<MapAnnotation> ()
                            .Select (s => MKMapPoint.FromCoordinate (s.Coordinate))
                            .ToArray ();            

    map.SetVisibleMapRect(MKPolygon.FromPoints (points).BoundingMapRect, true); 
}

Answer 23

考虑此扩展程序：

extension MKCoordinateRegion {
    init(locations: [CLLocationCoordinate2D], marginMultiplier: Double = 1.1) {
        let mapRect = locations.reduce(MKMapRect(), {
            let point = MKMapPointForCoordinate($1)
            let rect = MKMapRect(origin: point, size: MKMapSize(width: 0.0, height: 0.0))
            return MKMapRectUnion($0, rect)
        })

        var coordinateRegion = MKCoordinateRegionForMapRect(mapRect)
        coordinateRegion.span.latitudeDelta *= marginMultiplier
        coordinateRegion.span.longitudeDelta *= marginMultiplier
        self = coordinateRegion
    }
}

Answer 24

快速5版本：

   func regionFor(coordinates coords: [CLLocationCoordinate2D]) -> MKCoordinateRegion {
        var r = MKMapRect.null

        for i in 0 ..< coords.count {
            let p = MKMapPoint(coords[i])

            r = r.union(MKMapRect(x: p.x, y: p.y, width: 0, height: 0))
        }

        return MKCoordinateRegion(r)
    }

定位MKMapView以一次显示多个注释

24 个答案: