Get Root ViewController of StoryBoard

   

UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:@"Main" bundle: nil];

    

    UINavigationController *NavController = (UINavigationController*)[mainStoryboard instantiateViewControllerWithIdentifier:@"NavController"];

    UIViewController *TheViewController=[[NavController viewControllers] objectAtIndex:0];

You need to specify the controller identifier for your navigation controller in the attributes inspector of the navigation controller

Resign First responder without knowing which one

[self.view endEditing:YES]

Get primitive type from NSNumber

 const char* type = [theValue objCType];
if (strcmp (type, @encode (NSInteger)) == 0)
{
    //It is NSInteger
}
else if (strcmp (type, @encode (NSUInteger)) == 0)
{
    //It is NSInteger
}
else if (strcmp (type, @encode (int)) == 0)
{
    //It is NSUInteger
}
else if (strcmp (type, @encode (float)) == 0)
{
    //It is float
}
else if (strcmp (type, @encode (double)) == 0)
{
    //It is double
}
else if (strcmp (type, @encode (long)) == 0)
{
    //It is long
}
else if (strcmp (type, @encode (long long)) == 0)
{
    //It is long long
}

Singleton Viewcontroller Storyboard

static id s_singleton = nil;

+ (id) alloc {

    if(s_singleton != nil)

        return s_singleton;

    return [super alloc];

}

- (id) initWithCoder:(NSCoder *)aDecoder {

    if(s_singleton != nil)

        return s_singleton;

    self = [super initWithCoder:aDecoder];

    if(self) {

        s_singleton = self;

    }

    return self;

}

implicit declaration of function 'inet_addr' is invalid in C99

#include < arpa/inet.h >

in .h 

Create Navigationcontroller in View based application

    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];

    self.viewController = [[[ViewController alloc] initWithNibName:@"ViewController" bundle:nil] autorelease];

    self.Nav=[[UINavigationController alloc] initWithRootViewController:self.viewController];

    

    [self.window setRootViewController:_Nav];

    

    [self.window makeKeyAndVisible];

    return YES;

iOS Device Resolutions Diagram