当试图编码引脚位置时，无法调用“MapAnnotation”

Question

我无法在XCode 4上调用类“MapAnnotation”。我正在编写允许将引脚放置在MKMapView中的编码。我相信我已经输入了正确的代表。下面是我有：

MillersLocations.h

#import <Foundation/Foundation.h> 
#import <MapKit/MKAnnotation.h> 
#import <MapKit/MapKit.h> 

@interface MillersLocations : NSObject <MKAnnotation> { 
    CLLocationCoordinate2D coordinate; 
    NSString *title; 
    NSString *subtitle; 
} 

@property (nonatomic, assign) CLLocationCoordinate2D coordinate; 
@property (nonatomic, copy) NSString *title; 
@property (nonatomic, copy) NSString *subtitle; 

@end 

MillersLocations.m

#import "MillersLocations.h" 

@implementation MillersLocations 
@synthesize coordinate, title, subtitle; 


-(void)dealloc{ 
    [title dealloc]; 
    [subtitle dealloc]; 
    [super dealloc]; 
} 

@end 

而且这里是我的地图视图视图控制器：

MapViewController.h

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

@interface MapViewController : UIViewController <MKMapViewDelegate> { 
    IBOutlet MKMapView *mapView; 

} 

@end 

MapViewController.m（只是部分我在看）

#import "MapViewController.h" 
#import "MillersLocations.h" 

@implementation MapViewController 

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil 
{ 
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]; 
    if (self) { 

    } 
    return self; 
} 

//skipping forward 

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 

    MKCoordinateRegion store1; 
    store1.center.latitude = 36.8605679; 
    store1.center.longitude = -76.2866713; 
    store1.span.latitudeDelta = 0.1; 
    store1.span.longitudeDelta = 0.1; 
    [mapView setRegion:store1 animated:YES];  

    //this is where I'm trying to put this code in: 
    MapAnnotation* annotation = [[MapAnnotation alloc] initWithCoordinate:newCoord]; 
    //BUT "MapAnnotation" isn't an option 
    } 

我想知道如果我没有进口权类什么的。我谷歌搜索了它，似乎无法找到“MapAnnotation”所在的位置。我需要导入什么来访问“MapAnnotation”？一切工作正常，直到那一点。

感谢您的帮助。我只是在学习这些东西！

Answer 1

是什么让你觉得有叫MapAnnotation的课？你的注解类被称为MillersLocations。您需要创建该类的实例并调用[mapView addAnnotation:millersLocationInstance];（或类似的东西）。