问题
I'm building an iOS application. Most of the application requires access to a persistent object. This object is instantiated when the app loads via the Application Delegate.
The problem I have is that numerous View Controllers that need to access this object.
What is the best way and best practice to create global objects that can be access from anywhere in the application?
Examples would be appreciated. Many thanks.
回答1:
You might want to look at the Singleton pattern. The linked article provides a pretty good description of it including how to implement one in Cocoa.
If the Singleton doesn't make sense in your context, and you still need the Global reference to your variable, you could just put a reference to it in your AppDelegate. (Not recommended)
It can be accessed from within your application anytime using:
[UIApplication sharedApplication] delegate]
来源：https://stackoverflow.com/questions/5721990/how-or-where-should-i-store-object-instances-that-i-require-globally-within-my-i