ios文档网址

仅做记录，以备查看而已：
1.blocks
https://developer.apple.com/library/content/documentation/Cocoa/Conceptual/Blocks/Articles/00_Introduction.html#//apple_ref/doc/uid/TP40007502

2.OpenglES
https://developer.apple.com/library/content/documentation/3DDrawing/Conceptual/OpenGLES_ProgrammingGuide/Introduction/Introduction.html

3.AVFoundation
https://developer.apple.com/library/content/documentation/AudioVideo/Conceptual/AVFoundationPG/Articles/00_Introduction.html#//apple_ref/doc/uid/TP40010188

4.AudioSession
https://developer.apple.com/library/content/documentation/Audio/Conceptual/AudioSessionProgrammingGuide/Introduction/Introduction.html#//apple_ref/doc/uid/TP40007875-CH1-SW1