window support, event support, and userinterface management, and it lets you create both text and web pages. It further acts as your interface to the accelerometers, the camera, the photo library, and devicespecific information.

　　Media is where you can get access to the major audio and video protocols built into the iPhone and iPad. Its four graphical technologies are OpenGL ES, EAGL (which connects OpenGL to your native window objects), Quartz (which is Apple’s vectorbased drawing engine), and Core Animation (which is also built on Quartz). Other frameworks of note include Core Audio, Open Audio Library, and Media Player.

　　Core Services offers the frameworks used in all applications. Many of them are data related, such as the internal Address Book framework. Core Services also contains the critical Foundation framework, which includes the core definitions of Apple’s objectoriented data types, such as its arrays and sets.

　　Core OS includes the kernel-level software. You can access threading, files, networking, other I/O, and memory.

　　iOS中的类

　　UIKit framework classe

　　UI开头的类，如UIView等classes most tightly connected to the devices, including all the graphical classes

　　Foundation framework classes

　　NS开头，主要基本数据结构的支持，如数组，字符串，Url, XML解析等

　　其他

　　Address Book framework

　　Address Book UI framework

　　Core Audio framework

　　Media Player framework

　　Core Graphics framework

　　Quartz Core framework

　　OpenGL ES framework

　　APNS framework：Push notification services

　　Map Kit framework: This framework provides you with a simple view that you can add anywhere you want a map to appear.

　　Store Kit framework: The Store Kit API allows you to sell various items within your application.

　　Core Foundation framework