id for the object instead. Weakly typed variables are used frequently for things such as collection classes, where the exact type of the objects in a collection may be unknown. If you are used to using strongly typed languages, you might think that the use of weakly typed variables would cause problems, but they actually provide tremendous flexibility and allow for much greater dynamism in Objective-C programs.- (void)viewWillAppear:(BOOL)animated
{
[self.navigationController setNavigationBarHidden:YES animated:animated];
[super viewWillAppear:animated];
}
- (void)viewWillDisappear:(BOOL)animated
{
[self.navigationController setNavigationBarHidden:NO animated:animated];
[super viewWillDisappear:animated];
}
If you're seeing this alert message in your device, which is not going away and sticking on screen then here's the solution.
In textfields, sometimes we need to show some default message which is a hint which disappears when gets focused or is in editing mode. So, for this do you the placeholder property of textfield.
// Add this line on top of your AppDelegate.m
#import "CoreLocationViewController.h"
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
// Override point for customization after application launch.
self.window.backgroundColor = [UIColor whiteColor];
CoreLocationViewController *myCoreLocationViewController = [[CoreLocationViewController alloc]
initWithNibName:@"CoreLocationViewController"
bundle:[NSBundle mainBundle]];
UINavigationController *nav = [[UINavigationController alloc]
initWithRootViewController:myCoreLocationViewController];
[[self window] addSubview:[nav view]];
[self.window makeKeyAndVisible];
return YES;
}
#import <UIKit/UIKit.h>
#import <CoreLocation/CoreLocation.h>
@interface CoreLocationViewController : UIViewController <CLLocationManagerDelegate> {
CLLocationManager *locationManager;
}
@property (retain, nonatomic) CLLocationManager *locationManager;
@property (retain, nonatomic) IBOutlet UILabel *locationLabelOne;
@property (retain, nonatomic) IBOutlet UILabel *locationLabelTwo;
@end
#import "CoreLocationViewController.h"
@implementation CoreLocationViewController
@synthesize locationManager;
@synthesize locationLabelOne;
@synthesize locationLabelTwo;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
[self setLocationManager:[[CLLocationManager alloc] init]];
[locationManager setDelegate:self];
[locationManager setDistanceFilter:kCLDistanceFilterNone];
[locationManager setDesiredAccuracy:kCLLocationAccuracyHundredMeters];
[locationManager startUpdatingLocation];
}
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
[locationLabelOne setText:[NSString stringWithFormat:@"%f", newLocation.coordinate.latitude]];
[locationLabelTwo setText:[NSString stringWithFormat:@"%f", newLocation.coordinate.longitude]];
}
I was developing an app where I needed to replace the existing buttons with the invisible ones, means in the background I've set my useful image that replaces buttons.