Objective-C (introduction to the Foundation framework) 05-Introduction to the foundation framework

Objective-C (introduction to the Foundation framework) 05-Introduction to the foundation framework
The so-called framework in iOS is a directory. iOS provides many frameworks that we can call in applications. Many applications use frameworks such as Foundation, UIKit, and Core Graphics. According to the template you selected for the application, the related framework has been automatically introduced. For example, when we create an Xcode project in CommandLineTool under OSX Application, the system will introduce the Foundation framework by default: # import <Foundation/Foundation. h> If the default framework cannot meet your application requirements, you can also add the framework you need. To use a framework, you need to add it to the project you created before your project can use it. When developing iOS projects, the most important frameworks used are the Foundation and UIKit frameworks. The Fundation framework provides basic system services for all applications, and the UIKit framework provides user interface-based classes.

Basic Framework for iOS

Framework name	Function
Foundation	Provides basic OC classes (such as NSObject and NSString) and basic data types.
UIKit	User Interface for creating and managing applications
QuartzCore	Provides animation effects and hardware rendering capabilities
CoreGraphics	Provides a C-based API for 2D rendering.
SystemConfiguration	Checks whether the current network is available and the status of hardware devices
AVFoundation	Provides underlying APIs for audio recording and playback, and manages audio hardware.
CFNetwork	Access and configure the network, such as HTTP, FTP, And Bonjour Services.
CoreFoundation	Provides abstract common data types, such as Unicode strings, XML, and URL.
CoreLocation	Use GPS and WIFI to get location information

 

GameKit	Provides network functions for games: point-to-point interconnection and voice communication in games
AddressBook	Provides the ability to access user contact information
AddressBookUI	Provides a user interface for displaying the contact information stored in the address book.
AudioToolBox	Provides underlying APIs for audio recording and playback, and manages audio hardware.
AudioUnit	Provides an interface for our applications to Process audio.
MapKit	Provides an embedded map interface for Applications
MediaPlayer	Supports video and audio playback.
MessageUI	Provides a view control interface to process E-mail and text messages.
OpenGLES	Provides animation effects and hardware rendering capabilities
StoreKit	Provides applications with support for consumption during program running.

And common third-party open-source frameworksAFNetworking and so on.

Foundation framework

(The framework in some official documents of apple is on the left, and header files of classes under some Foundation frameworks are displayed on the right)

The so-calledFoundation. frameworkThat is, Apple encapsulates some of our common classes into this framework. Common classes include NSString, NSDate, NSArray, NSDictionary, NSSet, and NSNumber. Classes in OC can be dividedImmutable)Class andMutable)Class, the Instance Object of the immutable class is called an immutable object, it refers to the object that cannot change its content after creation. A variable class instance object is called a variable object. It refers to an object that can change its content or status after being created. with Foundation, we can:

• Create and manage collections, such as arrays and dictionaries
• Access images and other resources stored in applications
• Create and manage strings
• Submit and receive notifications
• Creation date and time object
• Automatically discovers devices on an IP network.
• Operation URL stream
• Execute asynchronous code

　　Then, we need to learn about the classes provided by the system. We can:

1. Learn to useApplication Programming Interface (Application Programming Interface)Document

2. view the Class header file directly.

Option + left mouse button to enter the class API documentation (beginner)

Command + left-click to enter the Class header file by viewing the header file, suitable for those who have a certain understanding of this class.

3. What keywords should I pay attention to when viewing the API documentation?

Which class does Inherits from inherit from?

Conforms to indicates which protocols the class follows

The Framework class is defined under that Framework

Availability: Which version of iOS does this class support?

Declared in statement