Mapkit問題

Question

我正在使用下面的代碼來顯示對象的位置。

- (void)viewDidLoad { 
[super viewDidLoad]; 
[self selectData]; 


locationManager = [[CLLocationManager alloc] init]; 
locationManager.delegate = self; 
locationManager.desiredAccuracy = kCLLocationAccuracyBest; 
locationManager.distanceFilter = kCLDistanceFilterNone; 
[locationManager startUpdatingLocation]; 

CLLocation *location = [locationManager location]; 

// Configure the new event with information from the location 
CLLocationCoordinate2D coordinate1 = [location coordinate]; 

//NSString *latitude = [NSString stringWithFormat:@"%f", coordinate1.latitude]; 
//NSString *longitude = [NSString stringWithFormat:@"%f", coordinate1.longitude]; 


mapView.showsUserLocation=YES; 
mapView.delegate=self; 

//MKMapView *mapView = (MKMapView*)self.view; 

CLLocationCoordinate2D coordinate; 

coordinate.latitude = coordinate1.latitude; 

coordinate.longitude =coordinate1.longitude; 

//mapView.region = ; 
[mapView setRegion:MKCoordinateRegionMakeWithDistance(coordinate, 2000, 2000)]; 
NSUInteger count = 1; 
[self setTitle:[NSString stringWithFormat:@"%i Memories",[memoryArray count]]]; 
for(int i = 0; i < [memoryArray count]; i++) { 
    MemoryData *m=[memoryArray objectAtIndex:i]; 

    //CGFloat latDelta = rand()*.035/RAND_MAX -.02; 

    //CGFloat longDelta = rand()*.03/RAND_MAX -.015; 
    coordinate.latitude=[m.lat floatValue]; 
    coordinate.longitude=[m.lon floatValue]; 

    CLLocationCoordinate2D newCoord = {coordinate.latitude, coordinate.longitude}; 

    MapDemoAnnotation* annotation = [[MapDemoAnnotation alloc]initWithCoordinate:newCoord andID:count++]; 
    [annotation setMemoryData:m]; 
    [annotation setTag:i]; 

    [mapView addAnnotation:annotation]; 

    [annotation release]; 

} 

}

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation { 

MKPinAnnotationView *pinView = (MKPinAnnotationView*)[mapView dequeueReusableAnnotationViewWithIdentifier:@"Pin"]; 

if(pinView == nil) { 

    pinView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"Pin"]; 

    pinView.pinColor = MKPinAnnotationColorRed; 
    int t=((MapDemoAnnotation*)annotation).tag ; 
    NSLog(@"Tag is %i ",t); 


    pinView.animatesDrop = YES; 
    pinView.canShowCallout = YES; 
    UIImageView *pinImageView = [[UIImageView alloc] initWithFrame:CGRectMake(-5, 0, 34, 34)]; 

    UIImage *pinImage = [[UIImage alloc] initWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"photo" ofType:@"JPG"]]; 

    pinImageView.image = pinImage; 

    //[pinImage release]; 

    //[pinView addSubview:pinImageView]; 

    //[pinImageView release]; 
    UIButton *btn = [UIButton buttonWithType:UIButtonTypeDetailDisclosure]; 

    btn.tag = t; 

    pinView.rightCalloutAccessoryView = btn; 


    //pinView.rightCalloutAccessoryView=pinImageView; 

} else { 

    pinView.annotation = annotation; 

} 

return pinView; 

}

-(void)mapView:(MKMapView *)mapView annotationView:(MKAnnotationView *)view calloutAccessoryControlTapped:(UIControl *)control { 

ViewItemList *list=[[ViewItemList alloc]init]; 
MemoryData *m=[memoryArray objectAtIndex:control.tag]; 

[list setMemoryData:m]; 
[self.navigationController pushViewController:list animated:YES]; 

}

如果我在iPod上測試它工作正常。 但它我測試iPhone或模擬器上它顯示以下錯誤。

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[MKUserLocation tag]: unrecognized selector sent to instance 0xac20da0' 

請幫

Answer 1

看來問題是，你的自定義類MapDemoAnnotation不是UIView一個子類，它實現了tag財產。根據你的錯誤，它認爲它是MKUserLocation的一個子類。

如果你在這方面的課程是好的，很可能你的演員陣容不工作。也許你過度使用括號？嘗試寫這樣的行：

MapDemoAnnotation *myDemo = (MapDemoAnnotation *) annotation; 
int t = myDemo.tag;