使用IBAction按钮缩放MapView

时间：2013-03-02 17:34:07

标签： ios ios6 mkmapview zoom ibaction

我有一个问题。我的当前位置以地图视图显示并居中，但地图区域不会放大。我尝试通过从didUpdateToLocation方法中取出span和region来获取Rob的建议，但我必须没有正确实现它。我不认为它在viewDidLoad中识别我对setRegion的调用，并且我的按钮无法被识别。请检查下面的代码，并指出错误。我的目标是能够使用IBAction按钮放大和缩小我的位置。

·H 

- (IBAction)zoomIn:(id)sender;

- (IBAction)zoomOut:(id)sender;
viewDidLoad中的

.m 

double miles = 0.5;

MKCoordinateSpan span;
span.latitudeDelta = miles/69.0;
span.longitudeDelta = miles/69.0;

MKCoordinateRegion region;
region.span = span;

[self.mapView setRegion:region animated:YES];

[self.mapView setUserTrackingMode:MKUserTrackingModeFollow animated:YES];

_mapView.mapType = MKMapTypeSatellite;
.m在我的didUpdateToLocation方法中。

[self.mapView setCenterCoordinate:newLocation.coordinate animated:YES];

.Zoom In：

- (IBAction)zoomIn:(id)sender 
{
    MKCoordinateSpan span;
    span.latitudeDelta = _mapView.region.span.latitudeDelta * 2;
    span.longitudeDelta = _mapView.region.span.latitudeDelta * 2;
    MKCoordinateRegion region;
    region.span = span;
    region.center = _mapView.region.center;

    [self.mapView setRegion:region animated:YES];
}

。缩小：

- (IBAction)zoomOut:(id)sender
{
     MKCoordinateSpan span;
     span.latitudeDelta = _mapView.region.span.latitudeDelta / 2;
     span.longitudeDelta = _mapView.region.span.latitudeDelta / 2;
     MKCoordinateRegion region;
     region.span = span;
     region.center = _mapView.region.center;

     [self.mapView setRegion:region animated:YES];
}

6 个答案:

答案 0 :(得分：10)

您可以根据需要获取当前region，将span乘以或除以2（除以放大，乘以缩小），然后设置region： 

- (IBAction)zoomIn:(id)sender {
    MKCoordinateRegion region = self.mapView.region;
    region.span.latitudeDelta /= 2.0;
    region.span.longitudeDelta /= 2.0;
    [self.mapView setRegion:region animated:YES];
}

- (IBAction)zoomOut:(id)sender {
    MKCoordinateRegion region = self.mapView.region;
    region.span.latitudeDelta  = MIN(region.span.latitudeDelta  * 2.0, 180.0);
    region.span.longitudeDelta = MIN(region.span.longitudeDelta * 2.0, 180.0);
    [self.mapView setRegion:region animated:YES];
}

如果您想让地图自动缩放到您的位置，您可以使用：

self.mapView.userTrackingMode = MKUserTrackingModeFollow;

如果您想手动执行此操作，可以执行以下操作。首先，定义一个类属性，以确定是否已经放大：

@property (nonatomic) BOOL alreadySetZoomScale;

然后更改您的didUpdateLocations（或didUpdateToLocation）以检查并设置一次缩放比例：

- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
    CLLocation* newLocation = [locations lastObject]; // if less than zero, then valid lat and long not found

    if (newLocation.horizontalAccuracy < 0)
        return;

    if (!self.alreadySetZoomScale)
    {
        MKCoordinateRegion region = MKCoordinateRegionMakeWithDistance(newLocation.coordinate, 1609, 1609); // 1 mile = 1609.34 meters
        self.mapView.region = region;
        [self.mapView setRegion:region animated:YES];
        self.alreadySetZoomScale = YES;
    }
    else
    {
        [self.mapView setCenterCoordinate:newLocation.coordinate animated:YES];
    }
}

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
    // if prior to iOS 6, use this old `MKMapViewDelegate` method, but call our
    // other routine.

    if (SYSTEM_VERSION_LESS_THAN(@"6.0"))
        [self locationManager:manager didUpdateLocations:@[newLocation]];
}

这基本上说，“如果我还没有放大，请根据newLocation设置区域，并在该位置周围设置一定数量的米，但如果我已经这样做了，那么只需设置中心坐标基于我当前的位置，但不要改变缩放比例（如果我已经放大或缩小）。这也做了一些条件iOS版本号逻辑（使用macros shown here），确保是否最终用户在6.0之前运行iOS，它将调用我们更新的方法。

顺便说一句，如果您在地图上显示用户位置（例如self.mapView.showsUserLocation = YES;），您可能希望此didUpdateLocations也删除与MKUserLocation相关联的叠加层在移动地图中心之前，否则它可以留下旧的叠加层：

[self.mapView removeOverlays:self.mapView.overlays];

答案 1 :(得分：1)

试试这个。但我还没有测试过。

- (IBAction)zoomIn:(id)sender {
      MKCoordinateSpan span;
      span.latitudeDelta = _mapView.region.span.latitudeDelta * 2;
      span.longitudeDelta = _mapView.region.span.latitudeDelta * 2;
      MKCoordinateRegion region;
      region.span = span;
      region.center = _mapView.region.center;

     [self.mapView setRegion:region animated:YES];
 }

 - (IBAction)zoomOut:(id)sender {
      MKCoordinateSpan span;
      span.latitudeDelta = _mapView.region.span.latitudeDelta / 2;
      span.longitudeDelta = _mapView.region.span.latitudeDelta / 2;
      MKCoordinateRegion region;
      region.span = span;
      region.center = _mapView.region.center;

     [self.mapView setRegion:region animated:YES];

 }

答案 2 :(得分：1)

好的，这就是我用来获取我的2个IBAction按钮（zoomIn和zoomOut）来使用我的mapView。当您打开应用程序时，将显示用户位置，并且地图会放大并以其为中心。然后，您可以使用按钮放大或缩小2倍。*非常感谢Rob给我指路。

·H 

- (IBAction)zoomIn:(id)sender;

- (IBAction)zoomOut:(id)sender;

的.m 

@interface LocationViewController ()

@property (nonatomic) BOOL alreadySetZoomScale;

@end



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


if (!_alreadySetZoomScale)
{
MKCoordinateRegion region = MKCoordinateRegionMakeWithDistance(newLocation.coordinate,    1609, 1609); // 1 mile = 1609.34 meters

self.mapView.region = region;
[self.mapView setRegion:region animated:YES];
_alreadySetZoomScale = YES;

}

else

{
[self.mapView setCenterCoordinate:newLocation.coordinate animated:YES];
}


- (IBAction)zoomIn:(id)sender {

MKCoordinateRegion region = self.mapView.region;
region.span.latitudeDelta /= 2.0;
region.span.longitudeDelta /= 2.0;
self.mapView.region = region;

}

- (IBAction)zoomOut:(id)sender {;

MKCoordinateRegion region = self.mapView.region;
region.span.latitudeDelta *= 2.0;
region.span.longitudeDelta *= 2.0;
self.mapView.region = region;

}

我还有其他一些对MKMapView的调用，比如self.mapView.showsUserLocation = YES;在viewDidLoad中，但就是这样。

答案 3 :(得分：0)

Swift 2.0：

使用扩展程序：

extension MKMapView{

 func zoomInPinAnnotationLocation(targetMapViewName : MKMapView?, delta: Double)
 {
  var region: MKCoordinateRegion = targetMapViewName!.region
  region.span.latitudeDelta /= delta
  region.span.longitudeDelta /= delta
  targetMapViewName!.region = region

 }
 func zoomOutPinAnnotationLocation(targetMapViewName : MKMapView?,delta: Double)
 {
  var region: MKCoordinateRegion = targetMapViewName!.region
  region.span.latitudeDelta *= delta
  region.span.longitudeDelta *= delta
  targetMapViewName!.region = region
 }

}

用法：

var mapViewZoomStepperValue: Double = -1.0
@IBOutlet weak var mapViewZoomStepper: UIStepper!

@IBAction func mapViewZoomStepperValueChanged(sender: AnyObject) {

  if (mapViewZoomStepper.value  > mapViewZoomStepperValue)
  {
   mapViewZoomStepperValue = mapViewZoomStepperValue + 1.0

//Zoom In
   detailMapView.zoomInPinAnnotationLocation(detailMapView, delta: 3.0)
  }
  else
  {
   mapViewZoomStepperValue = mapViewZoomStepper.value - 1.0

//Zoom Out
   detailMapView.zoomOutPinAnnotationLocation(detailMapView, delta: 3.0)
  }

 }

答案 4 :(得分：0)

斯威夫特3：

import GoogleMaps
import GooglePlaces
import CoreLocation
import UIKit

class LocationMapView: UIViewController, GMSMapViewDelegate, CLLocationManagerDelegate {

     @IBOutlet weak var mapView: GMSMapView!

     var mapViewZoomStepperValue: Float = 0.0
     @IBOutlet weak var mapViewZoomStepper: UIStepper!

     override func viewDidLoad() {
            super.viewDidLoad()

            mapViewZoomStepper.minimumValue = -100

        }

        @IBAction func mapViewZoomStepperValueChanged(_ sender: Any) {

            if (Float(mapViewZoomStepper.value) > mapViewZoomStepperValue){

                mapViewZoomStepperValue = Float(mapViewZoomStepper.value)
                zoomIn()

            }else{

                mapViewZoomStepperValue = Float(mapViewZoomStepper.value)
                zoomOut()

            }

        }

        func zoomIn() {

            print("Zoom in!!")
            if mapView.camera.zoom == mapView.maxZoom {
                return
            }

            let currentZoom = mapView.camera.zoom + 1
            mapViewZoomController(currentZoom)

        }

        func zoomOut() {

            print("Zoom out!!")
            if mapView.camera.zoom == mapView.minZoom {
                return
            }

            let currentZoom = mapView.camera.zoom - 1
            mapViewZoomController(currentZoom)

        }

        func mapViewZoomController(_ level: Float) {

            let point: CGPoint = mapView.center
            let coor: CLLocationCoordinate2D = mapView.projection.coordinate(for: point)
            let camera = GMSCameraPosition.camera(withLatitude: coor.latitude, longitude: coor.longitude, zoom: Float(level))
            mapView.animate(to: camera)

        }

}

答案 5 :(得分：-1)

你可以在3行代码中实现最基本的代码

var region: MKCoordinateRegion = self.mapView.region
region = MKCoordinateRegionMake(self.mapView.centerCoordinate, MKCoordinateSpanMake(0.005, 0.005));
self.mapView.setRegion(region, animated: true)
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