iOs app 101

iOS App 101
And how fun is it ?
by tomjpsun

12年7月5日星期四

About me

• MFC Certiﬁcate
• WDM driver (USB)


About me

• MFC Certiﬁcate • Linux driver
• WDM driver (USB) • iOS App


About me

• MFC Certiﬁcate • Linux driver
• WDM driver (USB) • iOS App

Not interest any more


Agenda
• Development Environment
• Objective-C
• Cocoa
• Design patterns
• UX
• References

Tested combinations

XCode
iOS ver OS X ver
ver

5.1 4.3 10.7(Lion)

• XCode 5.0 below 4.2 10.6.8(Leopard)

Strictly depends on


• https://developer.apple.com/programs/

iOS Dev Center
https://developer.apple.com/devcenter/ios/index.action


Provision proﬁle

Your Mac Dev Center

Demo
• Create an empty App
• Browse XCode features
• organizer
• project conﬁgurations
• simulator
• download
• debug

Object oriented


Message passing
[instance method];

寫 iOS 最先看習慣的就是中括號


Dynamism
objective-C runtime library


.h
#import <Foundation/Foundation.h>

@interface Fraction: NSObject
{
int numerator;
int denominator;
}
-(void) print;
-(void) setNumerator: (int) n;
-(void) setDenominator: (int) d;
@end


.m
#import "Fraction.h"

@implementation Fraction
-(void) print
{
NSLog(@"%i/%i", numerator, denominator);
}
-(void) setNumerator: (int) n
{
numerator = n;
}
-(void) setDenominator: (int) d
{
denominator = d;
}
@end


Multiple arguments
-(void) setTo: (int) n over: (int) d
{
numerator = n;
denominator = d;
}

int main (int argc, char *argv[])
{
Fraction *aFraction = [[Fraction alloc] init];
[aFraction setTo: 1 over: 3];
[aFraction print]; // -> 1/3
return 0;
}


Class method
{
int numerator;
int denominator;
}

@interface FractionFactory: NSObject

+(Fraction*) newFractionWithNumerator: (int)numerator
andDenominator: (int)denominator;

int main (int argc, char *argv[])
{
Fraction* f = [FractionFactory
newFractionWithNumerator: 1
andDenominator: 2];
}


Synthesized accessor
#import <Foundation/Foundation.h>

{
int numerator;
}
-(void) setNumerator: (int) n; // setter
-(int) numerator; // getter
@end

compiler generates getter/setter
@interface Fraction: NSObject @implementation Fraction
@property numerator; @synthesis numerator;
@end @end


Dot accessing property
[ instance setPoperty: 2];

is equal to

instance.property = 2;


self
• self like this in C++
- (id)init
{
self = [super init];
if (self) {
// Custom initialization
}
return self;
}


id

• something like void*
• useful at runtime


selector
• name of method , function literal
• compile time
SEL aSelector = @selector(methodName);

• run time
SEL aSelector = NSSelectorFromString(@"print");

NSString* selectorStr =

NSStringFromSelector(aSelector);
NSLog(@"%@", selectorStr);


selector
[friend performSelector:@selector(gossipAbout:)

withObject:aNeighbor];

is equal to

[friend gossipAbout:aNeighbor];


Runtime
library
彈性：原本在 compile
time, link time 要做的動
作，延到 run time 再做


object A
-(void)fly

完全沒有任何繼承關係

object B
-(void)fly

SEL userSelector = NSSelectorFromString(@”fly”);
[ any performSelector: @selector(userSelector) ];

any 指向 object A, 就呼叫 A 的 fly
any 指向 object B, 就呼叫 B 的 fly


Category
• extending class (even if you don’t have the
source)
#import "High.h"

@interface High (calculate)
- (NSInteger) plus:(NSInteger)operand1 and:(NSInteger)operand2;
@end

@implementation High (calculate)
- (NSInteger) plus:(NSInteger)operand1 and:(NSInteger)operand2
{
return operand1 + operand2;
}
@end


Class extension
• category without name
• used as private method declaration in Obj-
C


Category may cause
chaos

• category wins over the override function
• deﬁne same function in different
categories. Lead to undeﬁned condition.


@protocol

• class with only methods.
• classes 之間說好要提供哪些 functions.
@protocol MyXMLSupport

- initFromXMLRepresentation:(NSXMLElement *)XMLElement;

- (NSXMLElement *)XMLRepresentation;

@end


memory management

• MRC - manual reference counting
• ARC - automatic reference counting
• garbage collection - in OS X, not in iOS


MRC
• Apple’s rule - owner release (owner: copy,
alloc, retain)
• burden on developers
// retain release pair
id value = [dict retain];
[value release];

// autorelease
array = [[NSMutableArray new] autorelease];


ARC

• supported on LLVM 3.0
• generate release code for you.


Blocks
this section is borrowed from WWDC 2011, sec. “block
and central dispatch”

* ^

Functions Blocks
// body of code // body of code
{ {

return a - b; return a - b;

} }

// pointer to a function // pointer to a block
* ^


Functions Blocks
{ {


} }

int (*cmpr)(int, int); int (^cmpr)(int, int);


Functions Blocks
{ {


} }


typedef int (*func_t) typedef int (^block_t)
(int, int); (int, int);


Functions Blocks
{ {


} }



func_t cmpr = arg; block_t cmpr = arg;


Functions Blocks
{ {


} }



func_t cmpr = arg; block_t cmpr = arg;

cmpr(x, y); cmpr(x, y);


Functions Blocks
int my_cmp(int a, int b) ^(int a, int b)
{ {


} }


Functions Blocks

int my_cmp(int a, int b) ^(int a, int b)
{ {


} }

// usage // usage

sort(array, 10, my_cmp); sort(array, 10, ^(int a,
int b)
{
return a - b;
});


closure Blocks
// body of code

^(int a, int b)
{

return a - b;

}


closure Blocks
// body of code
__block int cnt = 0;
^(int a, int b)
{
cnt++ ;
return a - b;

}

log(“Count: %d”, cnt);


Cocoa ﬁt in iOS

不管任何種類的 App，⼀一定會用到 UIKit


UIKit Philosophy
• MVC


View Controllers


Anatomy


View Controllers
Manage Views


View


Important Documents

View Controller Programming Guide for iOS
View Programming Guide


delegate
iOS
UIApplication
object

MyApp
delegate
implemented via @protocol


delegate
iOS
UIApplication
object

App 可以開始嗎？
MyApp
delegate


delegate
iOS
UIApplication
object
可以

App 可以開始嗎？
MyApp
delegate


delegate
iOS
UIApplication
object

App 將要結束！
MyApp
delegate


delegate
iOS 不用回答，因為只
UIApplication
object
是知會你的 App

App 將要結束！
MyApp
delegate


delegate
iOS
UIApplication
object

@protocol

MyApp
delegate


delegate
iOS
UIApplication
object some delegates
are optional

@protocol

MyApp
delegate


delegate

• no need to subclassing everywhere.
• de-coupling decision, cleaner design.


delegate demo

https://github.com/tomjpsun/TestObjc.git


Data-Source
• nearly the same as delegate, 但是提供 data
而非 UI 決策.

有幾個 sections ?

4
TableView
sec 1 cell 1 Controller
“Clear History”


Data-Source
• nearly the same as delegate, 但是提供 data
而非 UI 決策.

有幾個 sections ?

4
TableView Data Source
sec 1 cell 1 Controller
“Clear History”


Target-Action
Button
send message when the
event occurs
ViewController
-(void)myButtonPressed:
- (void)viewDidLoad
{
[super viewDidLoad];
! [self.myButton addTarget:self
action:@selector(myButtonPressed:)
forControlEvents:UIControlEventTouchUpInside];
}

- (void)myButtonPressed:(UIButton*)button
{
...
}


Notification
observer 1

Notification
anObject observer 2
Center
post
notification observer 3
broadcast
notification

reduce the code coupling


Singleton
request 1
request 1
response 1
Typical class response 1 A Singleton
A
response 2
request 2
response 2
B request 2

• 系統內，只能有⼀一份 instance，以某種標
準的 shared 方式共用之.


Singleton

• 是好的 design pattern ? 正反面討論很多
• Cocoa 很多用到 singleton pattern
Notiﬁcation
UIApplication NSFileManager
Center


abstract from the “Tap Worthy” book

Get it done quick

你想要做的



Get it done quick

你想要做的

使用者實際需要的



依使用習慣分類

• 微任務化
• 找在地資訊
• 排遣無聊



拇指習慣

左上和右上角，比較不容易按



神奇的 44

手指可觸碰到的最小的限度

Agenda
• Development Environment
• Objective-C
• Cocoa
• Design patterns
• UX
• References 勸敗時間到了！

Objective-C 入門

http://www.amazon.com/Programming-Objective-C-2-0-2nd-Edition/dp/0321566157


Cocoa 入門

http://www.amazon.com/Cocoa-Design-Patterns-Erik-Buck/dp/0321535022/ref=sr_1_1?
s=books&ie=UTF8&qid=1341483494&sr=1-1&keywords=cocoa+design+patterns


Online Videos

• CS193p in iTunes U(niversity)


User Experience

http://www.amazon.com/Tapworthy-Designing-Great-iPhone-Apps/dp/1449381650/
ref=sr_1_1?s=books&ie=UTF8&qid=1341483149&sr=1-1&keywords=tapworthy


唯⼀一免費的

XCode documents


唯⼀一免費的

XCode documents

免費的最硬


Q &A


iOs app 101

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