摘要： 1. NSAutoreleasePool' is unavailable: not available in automatic reference counting modeX-code 4.2,苹果引入了自动记算引用数的功能，所以老的项目中NSAutoreleasePool* pool = [[NSAutoreleasePoolalloc]init];是报错的，必须把arc（auto-reference-command）关闭才行,方法如下：Build settings--->Apple LLVM compiler 3.0- Language--->Objective-C 阅读全文