The document provides an overview of iOS app development basics including building a "Hello World" app, application architecture and states, coding in Objective-C, short message sending, storyboarding, and static table views. It discusses setting up an Xcode project, the app delegate, view controllers, windows, and application states like active, background, and suspended. It also covers Objective-C basics like properties, accessors, and blocks.

2. -Hussain KMR Behestee
Software Engineer
The JAXARA IT Ltd.
[Session-1]

3. Agendas
 iOS App Dev Basics
 Building Hello World App
 Application Architecture
 Application States
 Coding in Objective C
 Short Message Send
 Storyboarding
 Static Table View

4. iOS App Dev Basics
 Cocoa Touch Framework
 iOS SDK
 XCode
 Objective-C
 iTunes-Store/App Store

5. Setup
Go this URL for details

6. Building Hello World App
 Start XCode
 Choose Create New XCode
Project  Getting idea about
 Choose Tabbed Application  Templates
and press Next  Nib File, Interface Builder
 Enter Necessary Information  Simulator
and press Next  UI Objects
 Locate where to save and
press Create. Your Project
will be created.
 Now Press Run Button, The
application will be run in
simulator.

7. Application Architecture
main
App Delegate
View
Controller
Main Window
View Controller
Screen view

8. Application Architecture
App The app delegate is a custom object created at app launch time, usually by the
delegate UIApplicationMain function. The primary job of this object is to handle state
transitions within the app. For example, this object is responsible for launch-time
initialization and handling transitions to and from the background. For information
about how you use the app delegate to manage state transitions, see Managing
App State Changes”
View View controller objects manage the presentation of your app’ s content on screen. A
controller view controller manages a single view and its collection of subviews. When presented,
the view controller makes its views visible by installing them in the app’ s window.
The UIViewController class is the base class for all view controller objects. It provides
default functionality for loading views, presenting them, rotating them in response to
device rotations, and several other standard system behaviors. UIKit and other
frameworks define additional view controller classes to implement standard system
interfaces such as the image picker , tab bar interface, and navigation interface.
UIWindow A UIWindow object coordinates the presentation of one or more views on a screen.
Most apps have only one window, which presents content on the main screen, but apps
may have an additional window for content displayed on an external display .
T o change the content of your app, you use a view controller to change the views
displayed in the corresponding window. Y ou never replace the window itself .
In addition to hosting views, windows work with the UIApplication object to deliver
events to your views and view controllers.

9. Application Architecture

10. IDE - XCode

11. Another Hello World App
For walking step by step visit: Hello World App

12. Another Hello World App (Cont.)

13. Application States
The app has not been launched or was running but was terminated by the
Not running
system.
The app is running in the foreground but is currently not receiving events.
Inactive (It may be executing other code though.) An app usually stays in this state
only briefly as it transitions to a different state.
The app is running in the foreground and is receiving events. This is the
Active
normal mode for foreground apps.
The app is in the background and executing code. Most apps enter this state
briefly on their way to being suspended. However, an app that requests extra
execution time may remain in this state for a period of time. In addition, an
Background
app being launched directly into the background enters this state instead of
the inactive state. For information about how to execute code while in the
background, see “Background Execution and Multitasking.”
The app is in the background but is not executing code. The system moves
apps to this state automatically and does not notify them before doing so.
Suspended While suspended, an app remains in memory but does not execute any code.
When a low-memory condition occurs, the system may purge suspended
apps without notice to make more space for the foreground app.

14. Application States
 application:willFinishLaunchingWithOptions:This method is your app’ s first
chance to execute code at launch time.
 application:didFinishLaunchingWithOptions:—This method allows you to
perform any final initialization before your app is displayed to the user.
 applicationDidBecomeActive:—Lets your app know that it is about to become the
foreground app. Use this method for any last minute preparation.
 applicationWillResignActive:—Lets you know that your app is transitioning away
from being the foreground app. Use this method to put your app into a quiescent state.
 applicationDidEnterBackground:—Lets you know that your app is now running in
the background and may be suspended at any time.
 applicationWillEnterForeground:—Lets you know that your app is moving out of
the background and back into the foreground, but that it is not yet active.
 applicationWillTerminate:—Lets you know that your app is being terminated. This
method is not called if your app is suspended.

15. Objective-C Basics

16. Objective-C Basics
 By default, these accessor methods are synthesized
automatically for you by the compiler, so you don’t need to
do anything other than declare the property using
@property in the class interface.
 @property NSString *firstName;
 NSString *firstName = [somePerson firstName];
 [somePerson setFirstName:@"Johnny"];
 The method used to access the value (the getter method)
has the same name as the property.
 The method used to set the value (the setter method) starts
with the word “set” and then uses the capitalized property
name.

17. Objective-C Basics
 If you don’t want to allow a property to be changed via
a setter method
 @property (readonly) NSString *fullName;
 If you want to use a different name for an accessor
method
 @property (getter=isFinished) BOOL finished;
 If you need to specify multiple attributes, simply
include them as a comma-separated list
 @property (readonly, getter=isFinished) BOOL
finished;

18. Objective-C Basics
 Available Attributes are
 readwrite - Indicates that the property should be treated as read/write. This is
default.
 readonly - Indicates that the property is read-only
 strong - Specifies that there is a strong (owning) relationship to the destination object
 weak - Specifies that there is a weak (non-owning) relationship to the destination
object.
 copy - Specifies that a copy of the object should be used for assignment.
 assign - Specifies that the setter uses simple assignment. This is default.
 retain - Specifies that retain should be invoked on the object upon assignment.
 nonatomic - Specifies that accessors are nonatomic. By default, accessors are atomic
 How to use:
 In Interface @property(copy, readwrite) NSString *value;
 In Implement @synthesize value; or
 @synthesize value=@“somevalue”;

19. Blocks - Anonymous Function
• Blocks are objects that encapsulate a unit of work—that is, a segment of
code—that can be executed at any time.
• A caret (^) is used as a syntactic marker for blocks.

20. Short Message Send
 Syntax
 [receiver message]
 Example
 [myRectangle display];
 [myRectangle setWidth:20.0];
 [myRectangle setOriginX: 30.0 y: 50.0];
 When the Params are optional
 [receiver makeGroup:group, memberOne, memberTwo,
memberThree];
 Nested messaging
 [myRectangle setPrimaryColor:[otherRect primaryColor]];
 Message chaining
 x = [[[person address] street] name];

21. Storyboarding
Step by step Storyboarding
Using View Controllers in Storyboarding Application

22. Static Table View
 In the Attributes inspector, choose Static Cells in the
Content pop-up menu.