Google地图实现之二
它有很多方法和属性，不过如果只是想得到基本的定位功能的话，只需实例化一个对像然后加到当前的
view上就可以了。
<一>先介绍一下，它的几个常用的属性。
region 用来设置地图的那一部份被显示，它是一个结构体,定义如下：
typedef struct{
CLLocationCoordinate2D center;//表示显示的中心
MKCoordinateSpan span; //表示比例
}MKCoordinateRegion;
对于MKCoordinateSpan其定义如下：
typedef struct{
CLLocationDegrees latitudeDelta;//这类型在前一节中讲过了，是double型的
CLLocationDegrees longitudeDlta;
}MKCoordinateSpan;
再看一下maptype属性，它用于设置地图的类型，如下所示：
MapType属性值 描述
MKMapTypeStandard 表示标准的街道级地图
MKMapTypeSatellite 表示卫星图
MKMapTypeHybird 表示上面两者的混合
其余的就不再一一介绍了，去看看相关的文档即可，在这里已经可以把地图弄出来了。
<二>下面我们把上一节中的代码改一下：
.h头文件
#import <UIKit/UIKit.h>
#import <CoreLocation/CoreLocation.h>
#import <MapKit/MapKit.h>
@interface CoreLocationViewController : UIViewController
<CLLocationManagerDelegate,MKMapViewDelegate>{
MKMapView *map;
CLLocationManager *locManager;
CLLocationCoordinate2D loc;
}
@property (nonatomic, retain) MKMapView *map;
@property (nonatomic, retain) CLLocationManager *locManager;
- (void)setCurrentLocation:(CLLocation *)location;
@end
.m源文件
#import "CoreLocationViewController.h"
@implementation CoreLocationViewController
@synthesize map;
@synthesize locManager;
- (void)viewDidLoad {
map = [[MKMapView alloc]initWithFrame:CGRectMake(0.0f, 0.0f, 320.0f, 411.0f)];
map.showsUserLocation = YES;
[self.view addSubview:map];
locManager = [[CLLocationManager alloc] init];
locManager.delegate = self;
locManager.desiredAccuracy = kCLLocationAccuracyBest;
locManager.distanceFilter = 100;
[locManager startUpdatingLocation];
[super viewDidLoad];
}
/*
- (IBAction) segmentChange:(id)sender {
if (segmentControl.selectedSegmentIndex == 0) {
map.mapType = MKMapTypeStandard;
}
if (segmentControl.selectedSegmentIndex == 1) {
map.mapType = MKMapTypeSatellite;
}
if (segmentControl.selectedSegmentIndex == 2) {
map.mapType = MKMapTypeHybrid;
}
}*/
- (void)dealloc {
[map release];
[locManager release];
[super dealloc];
}
#pragma mark -
#pragma mark Core Location Delegate Methods
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation {
NSLog(@"---------------");
loc = [newLocation coordinate];
MKCoordinateRegion region;
MKCoordinateSpan span;
span.latitudeDelta=0.1; //zoom level
span.longitudeDelta=0.1; //zoom level
NSLog(@"%f",loc.latitude);
NSLog(@"%f",loc.longitude);
region.span=span;
region.center=loc;
// map.showsUserLocation=NO;
map.mapType = MKMapTypeStandard;
[map setRegion:region animated:YES];
[map regionThatFits:region];
}
- (void)locationManager:(CLLocationManager *)manager
didFailWithError:(NSError *)error{
NSString *errorMessage;
if ([error code] == kCLErrorDenied){
errorMessage = @"被拒绝访问";
}
if ([error code] == kCLErrorLocationUnknown) {
errorMessage = @"";
}
UIAlertView *alert = [[UIAlertView alloc]
initWithTitle:nil
message:errorMessage
delegate:self
cancelButtonTitle:@"纭畾"
otherButtonTitles:nil];
[alert show];
[alert release];
}
- (void)setCurrentLocation:(CLLocation *)location {
MKCoordinateRegion region ;
region.center = location.coordinate;
region.span.longitudeDelta = 0.15f;
region.span.latitudeDelta = 0.15f;
[map setRegion:region animated:YES];
}
@end
效果如下图所示
