警告ARC解决办法 warning This file must be compiled with ARC
#warning This file must be compiled with ARC. Use -fobjc-arc flag (or convert project to ARC).
这个文件必须使用arc,需要在.m的compiler flags中添加-fobjc-arc
#warning This file must be compiled with ARC. Use -fobjc-arc flag (or convert project to ARC).
这个文件必须使用arc,需要在.m的compiler flags中添加-fobjc-arc