This document provides an overview of developing applications for the iPhone using Objective-C and the UIKit framework. It discusses Objective-C concepts like classes, memory management, categories and protocols. It also covers the iPhone UIKit including views, navigation controllers, tab bar controllers and table views. Other topics include data storage options like property lists, SQLite and web services. Sample code is provided to demonstrate various Objective-C and iPhone programming concepts.

1. iPhone
Objective-C, UIKit
bofeng@corp.netease.com
@vonbo

2. Agenda
• overview
• objective-c
• iPhone UIKit

3. overview

4. First iPhone App
• Hello world!

5. Things we have
• Hello world!

6. • xcode SDK
• & test with Simulator
• test with iPhone/iPod touch ($99)
• appstore
•

7. iPhone VS Android

8. objective-c

9. Objective C
•
•
• runtime
• foudation framework: values and collection classes
•
• category
• protocol

10. Sample Code
hello world

12. objective c
• @
• @interface, @implementation, @class
• @property, @synthesize
• @protocol
• NSString* str = @”hello world”
• [receiver message]
• C C++

17. Sample Code
class and message

18. runtime
• id
• class & className
• respondsToSelector
• performSelector
• isKindOfClass (super class included)
• isMemberOfClass
• @selector

19. @selector
• SEL
• C++

22. action
CGRect rect = CGRectMake(20, 20, 100, 30);
UIButton* myButton = [UIButton
buttonWithType:UIButtonTypeRoundedRect];
myButton.frame = rect;
[myButton setTitle:@"my button"
forState:UIControlStateNormal];
[myButton addTarget:self action:@selector(btnClick:)
forControlEvents : UIControlEventTouchUpInside];
[self.view addSubview:myButton];

23. Sample
runtime & selector

24. Foundation Framework
• Value and Collection Classes
• User defaults
• Archiving
• Task, timers, thread
• File system, I/0
• etc ...

25. Value and Collection
Classes
• NSString & NSMutableString
• NSArray & NSMutableArray
• NSDictionary & NSMutableDictionary
• NSSet & NSMutableSet
• NSNumber [a obj-c object wrapper for basic C
type]
• (NSNumber* num = [NSNumber
numberWithInt:3])

26. Sample Code
collection classes

27. • alloc new
• alloc&dealloc C++ new&delete
• but with ...

28. • alloc new copy
1.
retain
release
• 0
Obj-C dealloc
dealloc
dealloc

29. Sample Code
“ ” ...
memory management

30. Getter & Setter
@property & @synthesize

31. • new alloc copy
1.
release
•
retain release

32. but how to solve this ?
- (Person*) getChild {
Person* child = [[Person alloc] init];
[child setName:@”xxxx”];
....
// will return ... [child release] or not ?
return child;
}

33. Autorelease
• NSAutoreleasePool* pool ...
• [object autorelease]
• autorelease
NSAutoreleasePool
release

34. That’s why create pool
first ...
int main(int argc, char* argv[]) {
NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
// put your own code here ...
[pool release];
}

35. how to solve this ?
- (Person*) getChild {
Person* child = [[Person alloc] init];
[child setName:@”xxxx”];
....
// will return ... [child release] or not ?
return [child autorelease];
}

36. Autorelease Pool
•
• NSMutableArray pool
• autorelease Array
• pool Array
release
• autorelease pool
autorelease
pool pool

37. Autorelease Pool Stack
NSAutoreleasePool* poolFirst ..
for (int i=0; i < 10000; i++) {
NSAutoreleasePool* poolSecond ...
// have some autorelease object
// [object autorelease]
[poolSecond release];
}
// other code
[poolFirst release];

38. Autorelease Pool
•
• NSAutoreleasePool
• alloc release
• Autorelease pool retain
autorelease [pool retain] or [pool autorelease]
• AutoreleasePool “
”
• pool pool
iphone
release autorelease

39. • new alloc copy
1.
release autorelease
•
1
[NSString stringWithString:@”objc”]
•
retain release

40. Category

41. Sample Code
category

42. NSString Class
Cluster ...

43. Sample Code
something about class cluster ...

44. Category
•
•
•

45. Protocol
• familiar with C++ virtual class
• familiar with Java’s interface
•
• @optional
@required
warning required

46. protocol
@protocol TwoMethod
- (void) oneMethod;
- (void) anotherMethod;
@end

47. Class & Protocol
@interface MyClass : NSObject <TwoMethod> {
}
@end
@implementation MyClass
-(void) oneMethod {
// oneMethod’s implementation
}
- (void) anotherMethod {
// anotherMethod’s implementation
}
@end

48. Sample Code
protocol

49. Objective C
•
•
• runtime id, @selector, respondsToSelector ...
• foudation framework: values and collection classes
•
• category class cluster “ ”
• protocol

50. Using Objective-C Now !
• without mac
• ubuntu:
• sudo apt-get install gnustep gnustep-devel
• bash /usr/share/GNUstep/Makefiles/
GNUstep.sh
• GNUmakefile
• http://forum.ubuntu.org.cn/viewtopic.php?
t=190168

51. iPhone UIKit

52. iPhone Application
• &
• MVC
• Views (design & life cycle)
• Navigation based & Tab Bar based application
• very important TableView
•
• Web service

54. UIApplication
• Every application must have exactly one instance of
UIApplication (or a subclass of UIApplication). When
an application is launched, the UIApplicationMain
function is called; among its other tasks, this
function create a singleton UIApplication object.
• The application object is typically assigned a
delegate, an object that the application informs of
significant runtime events—for example, application
launch, low-memory warnings, and application
termination—giving it an opportunity to respond
appropriately.

57. UIApplicationMain
• delegateClassName
• Specify nil if you load the delegate object
from your application’s main nib file.
• from Info.plist get main nib file
• from main nib file get the application’s
delegate

61. UIControl
• UILabel
• UIButton
• UITableView
• UINavigatorBar
• ...

62. - design time

63. Demo
button click

64. Without IB ?
create a button and bind event by code

67. Views
• View view
superview subviews
• iphone app window Views
window window view (top level)
• view
• - (void)addSubview:(UIView *)view;
• - (void)removeFromSuperview;
• Superviews retain their subviews
• UIView CGRect CGPoint
CGSize

68. View’s life cycle & hook
function
• initWithNibName:bundle
• viewDidLoad
• viewWillAppear
• viewWillDisappear
• ...maybe viewDidUnload
• hook function
• shouldAutorotateToInterfaceOrientation
• didReceiveMemoryWarning

69. Navigation Controller

77. UINavigationController
• manages the currently displayed screens using the
navigation stack
• at the bottom of this stack is the root view controller
• at the top of the stack is the view controller currently
being displayed
• method:
• pushViewController:animated:
• popViewControllerAnimated:

78. Demo
UINavigationController

79. TabBar Controller

85. UITabBarController
• implements a specialized view controller that
manages a radio-style selection interface
• When the user selects a specific tab, the tab
bar controller displays the root view of the
corresponding view controller, replacing any
previous views
• init with an array (has many view controllers)

86. Demo
UITabBarController

87. Combine
• UI
• TabBarController Based +
NavigationController

90. Demo
Combine UITabBarController &
UINavigationController

91. TableView
• display a list of data
• Single column, multiple rows
• Vertical scrolling
• Powerful and ubiquitous in iPhone
applications

94. Display data in Table View
•
• Table views display a list of data, so use an array
• [myTableView setList:myListOfStuff];
•
• All data is loaded upfront
• All data stays in memory
•
• Another object provides data to the table view
• Not all at once
• Just as it’s needed for display
• Like a delegate, but purely data-oriented

103. Demo
UITableView <UITableViewDataSource>

106. Selection

108. Demo
UITableView <UITableViewDelegate>

109. UITabBar + UINavigation + UITableView !
NavigationController
TableViewController
TabBarController

110. Demo
UITabBar + UINavigation + UITableView

111. • Propery Lists, NSUserDefaults
• SQLite
• Core Data

112. SandBox
• Why keep applications separate?
• Security
• Privacy
• Cleanup after deleting an app

113. Sample: /Users/xxx/library/Application Support/iPhone Simulator/4.0/Applications

116. Property Lists
• Convenient way to store a small amount of data
• Arrays, dictionaries, strings, numbers, dates, raw data
• Human-readable XML or binary format
• NSUserDefaults class uses property lists under the hood
• When Not to Use Property Lists
• More than a few hundred KB of data
• Custom object types
• Multiple writers (e.g. not ACID)

119. Demo
Save data with NSUserDefaults

120. SQLite
• Complete SQL database in an ordinary file
• Simple, compact, fast, reliable
• No server
• Great for embedded devices
• Included on the iPhone platform
• When Not to Use SQLite
• Multi-gigabyte databases
• High concurrency (multiple writers)
• Client-server applications

122. SQLite Obj-C Wrapper
• http://code.google.com/p/flycode/source/browse/
trunk/fmdb
• A query maybe like this:
• [dbconn executeQuery:@"select * from call"]

124. Using Web Service
• Two Common ways:
• XML
• libxml2
• Tree-based: easy to parse, entire tree in memory
• Event-driven: less memory, more complex to manage state
• NSXMLParser
• Event-driven API: simpler but less powerful than libxml2
• JSON
• Open source json-framework wrapper for Objective-C
• http://code.google.com/p/json-framework/

125. NSURLConnection
• NSMutableURLRequest
• - connectionWithRequest: delegate
• delegate method:
• – connection:didReceiveResponse:
• – connection:didReceiveData:
• – connection:didFailWithError:
• – connectionDidFinishLoading:

126. Demo
use json-framework and NSURLConnection with hi-api

127. iPhone Application
• &
• MVC
• Views (design & life cycle)
• Navigation based & Tab Bar based application
& TableView
• (sandbox, property list,
sqlite)
• Web service

128. • Objective-C
• The iPhone Developer’s Cookbook
• Programming in Objective-C 2.0
•
• Stanford iPhone dev course
• iTunes iTune Store cs193p
mac windows

129. Q &A
The End