Reputation:
I have a project that is based on the Navigation Based Application template.
In the AppDelegate are the methods -applicationDidFinishLoading:
and -applicationWillTerminate:
. In those methods, I am loading and saving the application data, and storing it in an instance variable (it is actually an object-graph).
When the application loads, it loads MainWindow.xib, which has a NavigationConroller, which in turn has a RootViewController. The RootViewController nibName
property points to RootView (my actual controller class).
In my class, I wish to refer to the object that I created in the -applicationDidFinishLoading:
method, so that I can get a reference to it.
Can anyone tell me how to do that? I know how to reference between objects that I have created programmatically, but I can't seem to figure out to thread my way back, given that the middle step was done from within the NIB file.
Upvotes: 84
Views: 64057
Reputation: 3526
#define appDelegateShared ((AppDelegate *)[UIApplication sharedApplication].delegate)
In My Code:-
UIViewController *rootViewController = appDelegateShared.window.rootViewController;
Upvotes: 2
Reputation: 85542
If I understand your question, you want to reference member variables/properties in your AppDelegate object? The simplest way is to use [[UIApplication sharedApplication] delegate] to return a reference to your object.
If you've got a property called window, you could do this:
UIWindow *mainWindow = [[[UIApplication sharedApplication] delegate] window];
//do something with mainWindow
Upvotes: 16
Reputation: 31171
Here's a well defined portable alternative for iOS4.0 and up:
UIApplication *myApplication = [UIApplication sharedApplication];
UIWindow *mainWindow = [myApplication keyWindow];
UIViewController *rootViewController = [mainWindow rootViewController];
or, in one line,
UIViewController *rootViewController = [[[UIApplication sharedApplication] keyWindow] rootViewController];
Don't forget to set the window's rootViewController
property (say in IB) or this will do jack.
Upvotes: 11
Reputation: 3543
For variables (usually the model data structure) which I need to access it anywhere in the app, declare them in your AppDelegate class. When you need to reference it:
YourAppDelegate *appDelegate = (YourAppDelegate *)[[UIApplication sharedApplication] delegate];
//and then access the variable by appDelegate.variable
Upvotes: 204