iPhone 程式設計入門7) Cocoa Touch 摘要

(1) Cocoa Toch Frameworks

 

Foundation

• Object wrappers
  •     Strings,collections
  •     Various system services (file I/O and network)

 

 

• Subset of Foundation on Mac

UIKit

• Event handling
• Graphics and windowing
• Text and web management

(2) Foundation

• Strings
  NSString *myString = @"This is a string";
  
  NSString *myString = [NSString stringWithFormat:@"%d techTalks",24];
  
  NSString *pathString = @"Library/Caches/Images/dataCache.txt";
  NSArrary *pathComments = [pathString pathComments];
  NSString *fileName = [pathString lastPathComponent];
  
  NSString *fileContents = [NSString stringWithContentOfFile:pathString];
  
• Arrays
  • Mutable
    NSMutableArray *arr = [NSMutableArray array];
    [arr addObject:@"randomString"];
    
  • Immutable
    NSArray *arr = [NSArray arrayWithObjects:@"foo",@"bar",@"moof",nil];
    NSString *complexString = [arr componentsJoinedByString:@"--"];
    

 

 

• Dictionary
  • Mutable
    NSMutableDictionary *md = [NSMutableDictionary dictionaryWithCapacity:5];
    [md setObject:@"randomValue" forKey:@"randomKey"];
  • Immutable
    NSDictionary *dict = [NSDictionary dictionaryWithObjectAndKeys:
                                        @"valueOne",@"keyOne",@"valueTwo",@"keyTwo",nil];
    

 

 

• File I/O
  • NSFileManager class
    NSFileManager *fm = [NSFileManager defaultManager];
    if ([fm isWritableFileAtPath: path]) {
        [fm createFileAtPath: [path stringByAppendingPathComponent:@"foo.bar"]
                                                                                       contents:@"foo"
                                                                                        attributes:nil ];
    }
  • tmp directory -- Cleared,not backed up
  • Library/Caches -- Saved,not backed up
  • Everything else -- Backed up

 

 

• NSLog
  • NSLog(@"Simple debug statement");
  • NSLog(@"There are %d North American Tech Talk",numberOfNATechTalks);
  • NSLog(@"Got an array: %@",myArray);
  • NSLog(@"Got an dictionary: %@",myDictionary);

 

 

(3) Foundation Bundles -- a special kind of folder

• Executable
• User Interface (nib) files
• Metadata
• Resources
• Access via NSBundle class
• Easy accesses to static resources
  • Images
  • Sounds
  • Default data

 

 

• Read-only
  • Codesigning requires static bundle
  • Write new data to sandbox

 

 

• Accessing resources
  // Get an image from the main app bundle
  NSBundle *appBundle = [NSBundle mainBoundle];
  
  NSString *imagePath = [appBundle pathForResource:@"logo" ofType:@"png"];
  UIImage *logoImg = [[UIImage alloc] initWithContentsOfFile: imagePath];
  
  // Load a default SQLite DB if no user data exists
  NSString *defaultDB = [appBoundle pathForResource:@"db" ofType:@"sql"];
  if (sqlite3_open([defaultDB UTF8String],&database) == SQLITE_OK) {
         // fetch data from default db
  }

(4) Foundation -- Networking

• Standard sockets programming 
  • CFNetwork,CFSocket
  • POSIX

 

 

• NSURLConnection
  • Asynchronous request loading 

 

 

• NSXML
  • Basic parser

 

 

• Bonjour Networking
  • Zero-configuration discovery

 

 

• Bonjour discovery

(5) UIKit -- The UIKit Library,

 

• Buttons and Controls
• Image Views
• Web Views (put Safari inside your application)

(6) Application Design Patterns

• Model-View-Controller
• Foundation is for Model
• UIKit is for View
• iPhone SDK has ViewController class for Controller
• MVC is the umbrella design pattern 

(7) Application Design Patterns - Target-Action

 

 

 

(8) Application Design Patterns - Notification

 

• Notification Center
• Observer / Controller
• Notifications -- Registering an observer
  MPMoviePlayerController *mpc;
  NSURL *url = [NSURL urlWithString:@"http://foo.com/movie.mov"];
  mpc = [[MPMoviePlayerController alloc] initWithContentURL:url];
  
  // Register for device notifications
  [[NSNotificationCenter defaultCenter] addObserver:self
                                                               selector:@selector(movieLoaded:)
                                     name: MPMoviePlayerContentPreloadDidFinishNotification
                                     object:mpc];
  
  // Get preload notification and react accordingly
  - (void) movLoaded: (NSNotification *) notif {
          [(MPMoviePlayerController *)[notif object] play];
  }

(9) Application Design Patterns - Delegation

• The Application Life Cycle
  • Application launch
    • UIApplication
      • Main nib
      • Main window

     

     

    • Application delegate
      • UI config

     

     

   

   

 

 

• The Application Delegate 
  • Your first (and last) chance to act
    • Custom class written by you
    • Conforms to UIApplicationDelegate protocol
    • Hooked up in interface Builder

   

   

  • Two key methods
    • - (void) applicationDidFinishLaunching:(UIApplication*) app
      • Load initial UI,prepare saved state

     

     

    • - (void) applicationWillTerminate:(UIApplication*) app
      • Save state and data   

     

     

   

   

 

 

• Delegate Design Pattern 
  • Customization  without subclassing
    • Fine-tune default behavior
    • Respond to user actions
    • Separate controller from view

   

   

 

 

(10) iPhone Design Patterns

• Model-View-Controller
  • Target-Action
    • what reacts,and how
    • dynamic object and selector

   

   

  • Notification
    • information while app is running
    • Asynchronous delivery

   

   

  • Delegation
    • Direct control over view behavior
    • Synchronous delivery and response

   

   

 

 

(11) iPhone Development

• Get to know Cocoa Touch
  • Understand the Objective-C runtime
  • Explore Fundation and UIKit
  • Embrace design pattern
  • Look at example nib file
  • Use NSLog