AppDelegate的财产无法访问

Question

I create a property countryNameInitials as NSMutableArray in AppDelegate.m interface and synthesize it. The purpose is to store global data to display in table view. In the table view controller:

#import "AppDelegate.h"
...

@implementation
#define AppDelegate [[UIApplication sharedApplication] delegate]
...

The problem is that I cannot use AppDelegate.countryNameInitials to access the data. Any idea?

Answer 1

The fact is that

 [[UIApplication sharedApplication] delegate]

will give you a generic UIApplcationDelegate ; while you need your MyOwnAppDelegate (don't know how you called it) type to be able to use your countryNameInitials property. So, try with:

 #define AppDelegate ((MyOwnAppDelegate*)[[UIApplication sharedApplication] delegate])

then

AppDelegate.countryNameInitials

should work.

(I would not use the same name for the class and the macro, though).

Answer 2

The problem of accessing countryNameInitials is due to I declared the property in AppDelegate.m. After I move it to AppDelegate.h, errors are gone.

Side notes: 1. AppDelegate as the identifier name works for me. Naming conflicts suggested by @Vakio is not relevant.