变更记录

方案名称

地图 - MKMapView 地图开发相关总结

关键字

MKMapView \ CLLocationCoordinate2D \ CLLocation

需求场景

1. 需要实现地图显示需求时

参考链接

（无）

详细内容

1. 坐标

1. CLLocationCoordinate2D 与 NSString 之间的相互转换 ```objective-c

2. (CLLocationCoordinate2D) get2DCoordFromString:(NSString)coordString { CLLocationCoordinate2D location; NSArray coordArray = [coordString componentsSeparatedByString: @","]; location.latitude = ((NSNumber )coordArray[0]).doubleValue; location.longitude = ((NSNumber )coordArray[1]).doubleValue;

   return location; }

3. (NSString ) getStringFrom2DCoord :(CLLocationCoordinate2D)location { NSString aString = [NSString stringWithFormat:@"%f,%f",location.latitude,location.longitude]; return aString; } ```

2. 大头针

1. 定义一个遵循 MKAnnotation 协议的大头针数据模型 ```swift // // REXAnnotation.swift // REX // // Created by Alfred Jiang on 3/27/15. // Copyright (c) 2015 REX. All rights reserved. //

import UIKit import MapKit

class REXAnnotation: NSObject,MKAnnotation {

var coordinate: CLLocationCoordinate2D
var markerData: NSDictionary
//自定义一个初始化方法
init(coordinate: CLLocationCoordinate2D, markerData: NSDictionary) {
    self.markerData = markerData
    self.coordinate = coordinate
}

}

2. 添加到地图上
```swift
//定义地图
var mapViewLocation: MKMapView!

//添加大头针
var aLocationObject : REXAnnotation = REXAnnotation(coordinate: centerLocation, markerData : NSDictionary())
self.mapViewLocation.addAnnotation(aLocationObject)

//实现显示方法
//MARK: - MapKit

func mapView(mapView: MKMapView!, didAddAnnotationViews views: [AnyObject]!) {
    for mkaview in views
    {
        if mkaview is MKPinAnnotationView
        {
            (mkaview as MKPinAnnotationView).pinColor = MKPinAnnotationColor.Red
        }
    }
}

3. 地图以某坐标居中显示

1. MKMapView+MapViewUtil.h ```objective-c // // MKMapView+MapViewUtil.h // REX // // Created by Alfred Jiang on 3/27/15. // Copyright (c) 2015 REX. All rights reserved. //

import

@interface MKMapView (MapViewUtil)

• (void)setCenterCoordinate:(CLLocationCoordinate2D)centerCoordinate

              zoomLevel:(NSUInteger)zoomLevel
               animated:(BOOL)animated;
  

@end

2. MKMapView+MapViewUtil.m
```objective-c
//
//  MKMapView+MapViewUtil.m
//  REX
//
//  Created by Alfred Jiang on 3/27/15.
//  Copyright (c) 2015 REX. All rights reserved.
//

#import "MKMapView+MapViewUtil.h"

#define MERCATOR_OFFSET 268435456
#define MERCATOR_RADIUS 85445659.44705395

@implementation MKMapView (MapViewUtil)

#pragma mark -
#pragma mark Map conversion methods

- (double)longitudeToPixelSpaceX:(double)longitude
{
    return round(MERCATOR_OFFSET + MERCATOR_RADIUS * longitude * M_PI / 180.0);
}

- (double)latitudeToPixelSpaceY:(double)latitude
{
    return round(MERCATOR_OFFSET - MERCATOR_RADIUS * logf((1 + sinf(latitude * M_PI / 180.0)) / (1 - sinf(latitude * M_PI / 180.0))) / 2.0);
}

- (double)pixelSpaceXToLongitude:(double)pixelX
{
    return ((round(pixelX) - MERCATOR_OFFSET) / MERCATOR_RADIUS) * 180.0 / M_PI;
}

- (double)pixelSpaceYToLatitude:(double)pixelY
{
    return (M_PI / 2.0 - 2.0 * atan(exp((round(pixelY) - MERCATOR_OFFSET) / MERCATOR_RADIUS))) * 180.0 / M_PI;
}

#pragma mark -
#pragma mark Helper methods

- (MKCoordinateSpan)coordinateSpanWithMapView:(MKMapView *)mapView
                             centerCoordinate:(CLLocationCoordinate2D)centerCoordinate
                                 andZoomLevel:(NSUInteger)zoomLevel
{
    // convert center coordiate to pixel space
    double centerPixelX = [self longitudeToPixelSpaceX:centerCoordinate.longitude];
    double centerPixelY = [self latitudeToPixelSpaceY:centerCoordinate.latitude];

    // determine the scale value from the zoom level
    NSInteger zoomExponent = 20 - zoomLevel;
    double zoomScale = pow(2, zoomExponent);

    // scale the map’s size in pixel space
    CGSize mapSizeInPixels = mapView.bounds.size;
    double scaledMapWidth = mapSizeInPixels.width * zoomScale;
    double scaledMapHeight = mapSizeInPixels.height * zoomScale;

    // figure out the position of the top-left pixel
    double topLeftPixelX = centerPixelX - (scaledMapWidth / 2);
    double topLeftPixelY = centerPixelY - (scaledMapHeight / 2);

    // find delta between left and right longitudes
    CLLocationDegrees minLng = [self pixelSpaceXToLongitude:topLeftPixelX];
    CLLocationDegrees maxLng = [self pixelSpaceXToLongitude:topLeftPixelX + scaledMapWidth];
    CLLocationDegrees longitudeDelta = maxLng - minLng;

    // find delta between top and bottom latitudes
    CLLocationDegrees minLat = [self pixelSpaceYToLatitude:topLeftPixelY];
    CLLocationDegrees maxLat = [self pixelSpaceYToLatitude:topLeftPixelY + scaledMapHeight];
    CLLocationDegrees latitudeDelta = -1 * (maxLat - minLat);

    // create and return the lat/lng span
    MKCoordinateSpan span = MKCoordinateSpanMake(latitudeDelta, longitudeDelta);
    return span;
}

#pragma mark -
#pragma mark Public methods

- (void)setCenterCoordinate:(CLLocationCoordinate2D)centerCoordinate
                  zoomLevel:(NSUInteger)zoomLevel
                   animated:(BOOL)animated
{
    // clamp large numbers to 28
    zoomLevel = MIN(zoomLevel, 28);

    // use the zoom level to compute the region
    MKCoordinateSpan span = [self coordinateSpanWithMapView:self centerCoordinate:centerCoordinate andZoomLevel:zoomLevel];
    MKCoordinateRegion region = MKCoordinateRegionMake(centerCoordinate, span);

    // set the region like normal
    [self setRegion:region animated:animated];
}

@end

1. 使用

   self.mapViewLocation.setCenterCoordinate(centerLocation,zoomLevel: 14, animated: true)
   

效果图

（无）

备注

（无）