程序员的学习过程是无止境的，程序员学习的途径是多样的。可以从视频教程中领悟，也可以从他人的代码中理解。但当我们专注于某一个平台在开发的时候，对于某个API使用或者功能实现有疑问，通常简单的测试可以让我们知道可能的效果，异或网上搜索一下别人的经验，不过最好的途径应该还是阅读官方的文档解释。常常可以更全面，具体的了解。当然也不排除有时候官方文档说了跟没说似地，或者根本说得文不对题。
不过Apple的文档也有它独有的好处，比如绝大部分的文档都有相应的PDF格式文件提供下载，对于离线阅读十分的方便，而且还可以在PDF做一些相应的笔记，针对某几页进行打印等等。
另外，Apple还会给出该API所对应的框架结构使用的文档，其中会有一些代码例子。但是其实那些例子依然不够，还是需要到其它地方寻找。但是这些讲述结构的文档却是体现出API设计的来源，所以十分值得阅读，只是需要花时间了理解和消化。
在此，我简单文类罗列了一些我在学习和搜索的过程中看到的那些Apple官方的iOS开发相关的文档资料。其中粗体显示的文档，是我个人觉得比较有用的部分。你可以点击链接进行在线阅读。抑或在打开的页面点击右上角的PDF，下载下来阅读。因为之前一直都是下载来看的，都全部累积了下来，所以在文章的最后，我也放了链接提供全部文档的打包下载。
Computer Graphics
- OpenGL ES Programming Guide for iOS
- Animation Types and Timing Programming Guide
- Core Animation Programming Guide
- Core Animation Cookbook
- Core Image Programming Guide
- Quartz 2D Programming Guide
Objective-C
- Blocks Programming Topics
- Cocoa Fundamentals Guide
- Collections Programming Topics
- Error Handling Programming Guide
- Exception Programming Topics
- Advanced Memory Management Programming Guide
- Objective-C Runtime Programming Guide
- Object-Oriented Programming with Objective-C
- Programming with Objective-C
- Programming with Objective-C
- Objective-C Runtime Reference
- Memory Management Programming Guide for Core Foundation
Programming Guide
- Multimedia Programming Guide
- Archives and Serializations Programming Guide
- Core Data Programming Guide
- Key-Value Coding Programming Guide
- Key-Value Observing Programming Guide
- Resource Programming Guide
- Threading Programming Guide
- Notification Programming Topics
- Predicate Programming Guide
- Property List Programming Guide
- URL Loading System Programming Guide
- Preferences and Settings Programming Guide
- Bundle Programming Guide
- Document-Based App Programming Guide for iOS
- Event Handling Guide for iOS
- File System Programming Guide
- Concurrency Programming Guide
- iOS App Programming Guide
- Runtime Configuration Guidelines
- Local and Push Notification Programming Guide
- Location Awareness Programming Guide
- Distributed Objects Programming Topics
- Code Loading Programming Topics
- Dynamic Library Programming Topics
- File System Advanced Programming Topics
User Interface
- Drawing and Printing Guide for iOS
- Address Book Programming Guide for iOS
- iOS Human Interface Guidelines
- Table View Programming Guide for iOS
- Collection View Programming Guide for iOS
- Scroll View Programming Guide for iOS
- View Controller Catalog for iOS
- View Programming Guide for iOS
- View Controller Programming Guide for iOS
转自：http://blog.iderzheng.com/ios-development-official-documents/