chuanyituoku的专栏

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{ return 1;}- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *

The difference between an action method and a regular method: Nothing.An action method is really just the same as any other method. The only special thing is the (IBAction) specifier. This allows In

- (IBAction)showAlert{ UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Hello,World" message:@"This is my first app!"

- (void)viewDidLoad{    [superviewDidLoad];    // Do any additional setup after loading the view from its nib.        NSString *htmlFile = [[NSBundlemainBundle] pathForResource:@

If you have the imagination and perseverance there is no limit to what you can make these cool little devices do.pp16 start the first app Bull's EyeButtonpp27Alert View popuppp28ViewCo

1. create the second window by new file -> objective-C class (subclass ofViewController). then .xib, .h and .m2. set Action in the first view to trigger the second window - (IBAction)showI

Add a simple crossfade after the Start Over button is pressed, so the transition back to round one  won't seem so abrupt.pp146#import - (IBAction)startOver{    CATransition *tr

1 Set the Action in the second window2 in .m file, implement the - (IBAction)close method.pp 120// AboutViewController.m-(IBAction)close{    [self.presentingViewControllerdismiss

The delegation patternThe concept of delegation is very common in iOS. An object will often rely on another object to help it out with certain tasks. This separation of concerns keeps the system sim

Dictionaries cannot contain primitive values such as int and BOOL, only objects. The same thing goes for arrays. If you want to put an int or BOOL values into a dictionary or array, you have to conver

This is the second appHow it looks like pp2 : a to-do listThe app lets you organise to-do items into lists and then check off these items once you're done with them. You can set a reminder on a to

- (void)updateViewDateLabel{    NSDateFormatter *formatter = [[NSDateFormatteralloc] init];    [formatter setDateStyle:NSDateFormatterMediumStyle];    [formatter setTimeStyle:NSDateForma

MyLocations, an app that uses Core Location framework to obtain GPS coordinations for the user's whereabout, Map Kit to show the user's favourite locations on a map, the iPhone's camera and photo libr

To do that, we need to accomplish two things:1 Create a reference to the label so we can send it messages.2 Give the label new text to display@property (nonatomic,strong) IBOutletU

Properties and instance variables have a lot in common. In fact, when you use @synthesize to create the property, it is "backed" by an ivar. That means our slider property stores its value in an insta

//enable swipe-to-delete- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath{ [items removeObjectAtI

pp105property- (void)Done{    NSLog(@"Contents of the text field: %@",self.textField.text);        //close the window    [self.presentingViewControllerdismissViewControllerAnimated:YES

pp 67Add a navigation controllerOpen a new Add item screen that let the user type the text for items.- (IBAction)addItem{    int newRowIndex = [itemscount];        //Create

In Objective-C, protocol is simply a name for the groups of methods. A protocol doesn't have instance variables, and it doesn't implement any methods it declares. It just says, any object that conform

- (void)configureCheckmarkForCell:(UITableViewCell *)cell                withChecklistItem:(ChecklistsItem *)item{    UILabel *label = (UILabel *)[cellviewWithTag:1001];        label.text

Saving- (NSString *)documentsDirectory{    NSArray *paths =NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);//asd    NSString *documentsDirectory = [pat

To convert our app from portrait into landscape, we have to do three things:1 Make the view from BullsEyeViewController.xib landscape instead of portrait.2 Change one line of code in BullsEyeViewC

Do some setup after loading the view, typically from a nib.- (void)viewDidLoad{    [superviewDidLoad];// Do any additional setup after loading the view, typically from a nib.

These three steps are necessary for just about any property you add to the view controller if that property refers to a view in the nib:1 add @property to the .h file,2 connect the outlet in Inter

You can't really get a computer to generate numbers that are truly random and unpredictable, but we can employ a so-called pseudo-random generator to spit out numbers that at least appear that way.

1 Technically speaking youdon’t need tosetinstance variables to nilin dealloc, because the object will automatically release any instance variables when it gets deleted.