IOS/Objective-c：關於MKMapView的問題

Question

我是Objective-C/IOS的​​新手，我正在學習如何在地圖上實現用戶的當前位置。按照說明，但當我按下按鈕來查看我的當前位置，沒有任何反應。任何人都可以給我一個提示嗎？我使用的是最新版本的Xcode，我不知道，如果一個教程是一樣的...代碼：

ViewController.m：

#import "ViewController.h" 
#import "Pin.h" 


@interface ViewController() 

@end 

@implementation ViewController; 

@synthesize mapview; 

- (void)viewDidLoad { 
[super viewDidLoad]; 
MKCoordinateRegion region={{0.0,0.0},{0.0,0.0}}; 
region.center.latitude=38.711995; 
region.center.longitude=-9.144932; 
region.span.longitudeDelta=0.01f; 
region.span.latitudeDelta=0.01f; 
[mapview setRegion:region animated:YES]; 

Pin*vega =[[Pin alloc] init]; 
vega.title=@"Capela"; 
vega.subtitle=@"Bar"; 
vega.coordinate= region.center; 
[mapview addAnnotation:vega]; 

} 


- (void)didReceiveMemoryWarning { 
[super didReceiveMemoryWarning]; 
// Dispose of any resources that can be recreated. 
} 

-(IBAction)SetMap:(id)sender{ 

switch (((UISegmentedControl *) sender).selectedSegmentIndex) { 
    case 0: 
     mapview.mapType=MKMapTypeStandard; 
     break; 

    case 1: 
     mapview.mapType=MKMapTypeSatellite; 
     break; 

    case 2: 
     mapview.mapType=MKMapTypeHybrid; 
     break; 


    default: 
     break; 
    } 


} 


-(IBAction)GetLocation:(id)sender{ 
    mapview.showsUserLocation=YES; 

} 


(IBAction)Directions:(id)sender{ 
    NSString * urlString=@"http://maps.apple.com/maps?daddr=38.711995,  -9.144932"; 
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:urlString]]; 

} 

@end 

VieController.h：

#import <UIKit/UIKit.h> 
#import <MapKit/MapKit.h> 

@interface ViewController : UIViewController{ 

MKMapView * mapview; 

} 
@property(nonatomic,retain)IBOutlet MKMapView* mapview; 

-(IBAction)SetMap:(id)sender; 

-(IBAction)GetLocation:(id)sender; 

-(IBAction)Directions:(id)sender; 

@end 

而且在連接檢查一切（按鈕）設置..

Answer 1

你必須檢查/獲取位置權限：

它添加到您的plist文件

<key>NSLocationWhenInUseUsageDescription</key> 
<string></string> 

和代碼添加到您的VC：

if ([self.locationManager respondsToSelector:@selector(requestWhenInUseAuthorization)]) 
{ 
    [self.locationManager requestWhenInUseAuthorization]; 
}