keicoder

아이클라우드 이용 가능 여부 체크 (Checking for iCloud availability)

in application:didFinishLaunchingWithOptions method

id currentToken = [[NSFileManager defaultManager] ubiquityIdentityToken];
if (currentToken) {
NSLog(@"iCloud access on with id %@", currentToken);
} else {
NSLog(@"No iCloud access");
}

keicoder

Subclassing UIDocument 심플 예제

.h

@property (strong) NSString * noteContent;


.m

//Two override points, one when read and one when write.

keicoder

iCloud Setup on AppDelegate

- (void)setupiCloud
{
    dispatch_queue_t background_queue =
    dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT,
                              0);
    
    dispatch_async(background_queue, ^{
        

keicoder

아이폰과 아이패드의 인터페이스 오리엔테이션


1. XCode -> View based application 생성

2. ViewController -> UIImageView 삽입

3. Resources 그룹에 임의의 이미지 삽입. 이 이미지를 UIImageView의 디폴트 이미지가 되도록 수정.

4. ViewController.m 파일의 shouldAutorotateToInterfaceOrientation: 메소드를 다음과 같이 수정.

keicoder

distinction between an object and its class


//ice cream class
@interface IceCream : NSObject
@property (nonatomic, strong) NSString *flavor;
@property (nonatomic, assign) int scoops;
- (void)eatIt;
@end

keicoder

Structs

//for example :

typedef struct {
  CLLocationDegrees latitude;
  CLLocationDegrees longitude;
} CLLocationCoordinate2D;

keicoder

Finding the Current First Responder 

In iOS there is no simple call to retrieve the current first responder (without resorting to private APIs)

#import "UIResponder+FirstResponder.h"

static __weak id currentFirstResponder;

@implementation UIResponder (FirstResponder)

keicoder

Directory Paths on the iPhone and iPad

//The correct way to retrieve the path of the documents directory in iOS is, according to Apple Documentation:

NSArray *arrayPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docDir = [arrayPaths objectAtIndex:0];

//Objective-C class for the path of the documents directory

@interface Directories : NSObject {

keicoder

Handy UIKit Debugging Functions

//before
NSLog(@"self.bounds (%g,%g,%g,%g)"
self.bounds.origin.x,
self.bounds.origin.y,
self.bounds.size.width,
self.bounds.size.height);

//after : handy string conversions functions in UIKit

keicoder

assign and copy properties

Property with ’retain (or strong)’ attribute must be of object type

so, declare a property as assign if it has a primitive value 
@property (nonatomic, assign) int someNumber;

You also use assign for structs, because they aren’t objects either 
@property (nonatomic, assign) CLLocationCoordinate2D coordinate;