MKMapKit and the IOS4

Question

Hey all, I'm trying to get the MKMapView up and running however I can't seem to get past what seems to be a reference error. I've spent a few hours googling this as well as last night.

Header:

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

@interface MapsViewController : UIViewController {
    MKMapView *mapView;
}

@end

Main:

#import "MapsViewController.h"

@implementation MapsViewController
- (void)viewDidLoad {
    [super viewDidLoad];
    mapView = [[MKMapView alloc] initWithFrame:self.view.frame];
    [self.view insertSubview:mapView atIndex:0];
}

- (void)didReceiveMemoryWarning {
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];

    // Release any cached data, images, etc that aren't in use.
}

- (void)viewDidUnload {
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
}
- (void)dealloc {
    [super dealloc];
    [mapView dealloc];
}

@end

Error:

Build Maps of project Maps with configuration Debug

Ld build/Debug-iphonesimulator/Maps.app/Maps normal i386
cd /workspace/iphone_dev/Maps
setenv MACOSX_DEPLOYMENT_TARGET 10.6
setenv PATH "/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/gcc-4.2 -arch i386 -isysroot /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.1.sdk -L/workspace/iphone_dev/Maps/build/Debug-iphonesimulator -F/workspace/iphone_dev/Maps/build/Debug-iphonesimulator -filelist /workspace/iphone_dev/Maps/build/Maps.build/Debug-iphonesimulator/Maps.build/Objects-normal/i386/Maps.LinkFileList -mmacosx-version-min=10.6 -Xlinker -objc_abi_version -Xlinker 2 -framework Foundation -framework UIKit -framework CoreGraphics -o /workspace/iphone_dev/Maps/build/Debug-iphonesimulator/Maps.app/Maps

Undefined symbols:
  "_OBJC_CLASS_$_MKMapView", referenced from:
      objc-class-ref-to-MKMapView in MapsViewController.o
ld: symbol(s) not found
collect2: ld returned 1 exit status

I managed to find the MKMapKit.framework in the appropriate folders. Is they anything I'm missing?

Answer 1

Sounds like you need to add MapKit.framework to your project by right-clicking on your project list in Xcode and choosing Add->Existing Framework. Choose MapKit, and you should see it listed under Targets -> Your App -> Link Binary with Libraries.

Answer 2

What bosmacs said is correct. Also note that your dealloc method is incorrect.

- (void)dealloc {
  [mapView release];
  [super dealloc];
}

You should NEVER call dealloc on anything but super, and [super dealloc]; always goes at the end of your dealloc method.