IOS-Foundation framework structure and iosfoundation framework

IOS-Foundation framework structure and iosfoundation framework

These things can be used only when they are used. If they are used more often, remember them.

I found a good ios learning blog: http://www.cnblogs.com/kenshincui. it is very good. Please refer to it. The FOundation Series notes are used for personal review. Apart from books, you can also learn from other blog posts.

Foundation framework

It is the basis for IOS application development. There are more than 80 common frameworks, while foundation is the basis for all of them. It provides many basic object classes and data types, such as numbers, string, array, set, Dictionary, processing date and time, automatic memory management, file, archiving, and processing of geometric data structures. It provides basic data services for all applications,

The Foundation has nothing to do with the interface, and its prefix is NS.

In Foundation, some classes are only supported by mac OS, but not IOS.

What is Cocoa in IOS or mac OS?

Cocoa is not a programming language (it can run multiple programming languages), it is not a development tool (we can still develop Cocoa programs through the command line ), it is a native object-oriented API for creating Mac OS X and IOS programs, providing a programming environment for both applications. We are generally referred to as the "Cocoa framework ".

Cocoa is a collection of frameworks. It contains many sub-frameworks, including the most important "Foundation" and "UIKit ".

The former is the basis of the framework and has nothing to do with the interface, including a large number of common APIS; the latter is the basic UI class library, which will be frequently used in IOS development in the future. The positions of these two frameworks in the system are as follows:

All Mac OS X and IOS programs are composed of a large number of objects, and the root objects of these objects are NSObject. NSObject is in the Foundation framework. The specific class structure is as follows:

Generally divided:

UIKit is mainly used for interface architecture. Here we may also look at its class structure: