Solution for displaying compilation warnings or errors in release of iOS 5 xcode 4.2

From: http://www.2cto.com/kf/201109/105621.html

 
Since ios5 xcode4.2 introduces arc (automicreferencecounting), there are some minor changes when xcode4.2 is used to create a project.

NSAID utoreleasepool
@ {Autoreleasepool// Code for autoreleasepool} Block is replaced.

The _ strong and _ weak compilation commands are added.

Ios5.0 knows when your variables need to be release and autorelease. Therefore, do not write the variables as global. The global variables are replaced by single.

Solution: Disable it in the project.
The arc function. In the project properties, set object-C automatic reference counting to No. Otherwise, a red warning will be reported during compilation for memory-related operations such as release, retaincount, and retain.

For example, set it to No.