问题:

For my first time using Xcode I was following a tutorial online. I did everything as the tutorial showed me, but I am afraid that it's too outdated.

The error I encounter is:

[font_attributes release];

'release' is unavailable: not available in automatic reference counting mode

ARC forbids explicit message send of 'release'

My knowledge on Cocoa and Xcode is limited, but I still wish to expand my learning.

How may I fix the ARC issue?

回答1:

You have two options:

1) Turn off ARC for this project. This is done by setting 'Objective-C Automatic Reference Counting' to NO in the 'Build Settings' tab of your target in the project page.

2) Remove all retain release autorelease NSAutoReleasePools and retainCount calls, since ARC makes them for you. With the exception of NSAutoReleasePools They have been replaced by @autorelease{}.

The second option has been automated by apple see this question to use the refactoring tool.

回答2:

The two options given by NJones are valid and effective ways of dealing with ARC incompatibility. However, you do have a third option. Disabling ARC for specific files.

Giving the flags -fno-objc-arc to your non ARC compatible compile sources affectively marks them as such upon compilation.

You can find your compile sources under Targets → Your App → Build Phases → Compile Sources.