UI Foundation-ios Development Overview

1, an app based on two major elements

* Beautiful UI interface

* Practical functions

2. iOS system architecture

* iOS is based on Unix systems, and in terms of system stability, we can trust this system completely.

* The system architecture of iOS is divided into four tiers: Core OS layer, core service layer, media layer, and touch layer (Cocoa touch layers).

　　　　

--Touch Layer (Cocoa Touch): Provides a variety of useful frameworks for application development, and most of them are related to the user interface, which is essentially responsible for the user's touch interaction on the iOS device

Media Services layer: responsible for providing the graphics and sound APIs for building applications, using a variety of media files in your application, recording audio and video, drawing graphics, and animating the basics

Core Services Layer: This layer provides the hardware capabilities to access the core OS layer and includes the foundation framework. Because of this, this layer provides many of the underlying components needed to build an iOS application, such as strings, arrays, and other common data types. The core service layer can access some services of iOS, such as network connection, file access, database, user location, etc.

Core OS layer: This level includes many of the underlying components of the iOS operating system, including: System kernel, memory management, file system, power management, network components and device drivers, and can interact directly with hardware devices

* In the 4 tiers of iOS, we are primarily facing the Cocoa touch layer, which has a very important uikit framework in the COCOA touch layer that provides a variety of visual components for applications such as: Buttons (UIButton), switches (Uiswitch), Progress bar (Uiprogressview), etc.

* Other frameworks in the Cocoa touch layer are also very useful for the development of our applications! Such as: A framework for accessing the user's address book, a framework for obtaining photo information, a framework for hardware support such as acceleration sensors, etc.

3, iOS development needs to learn content

UI Foundation-ios Development Overview