I have an App Delegate and a 3 view controllers in my project. I have a variable(a NSMutable Array) in my App Delegate which I want to access from my view controllers. So I decided to create a pointer to my App Delegate and access the variables. Here is my code:
iSolveMathAppDelegate.h
#import <UIKit/UIKit.h>
@interface iSolveMathAppDelegate : NSObject <UIApplicationDelegate> {
UIWindow *window;
UITabBarController *tabBarController;
NSMutableArray *tmpArray;
}
@property (nonatomic, retain) IBOutlet UIWindow *window;
@property (nonatomic, retain) NSMutableArray *tmpArray; // variable I want to access
@property (nonatomic, retain) IBOutlet UITabBarController *tabBarController;
@end
iSolveMathAppDelegate.m
#import "iSolveMathAppDelegate.h"
@implementation iSolveMathAppDelegate
@synthesize window;
@synthesize tabBarController;
@synthesize tmpArray;
...
- (void)dealloc {
[tabBarController release];
[window release];
[tmpArray release];
[super dealloc];
}
@end
The view controller class from which I want to access the tmpArray.
referenceViewController.h
#import <UIKit/UIKit.h>
@class iSolveMathAppDelegate;
@interface referenceViewController : UITableViewController {
NSMutableArray *equationTypes;
iSolveMathAppDelegate *data;
}
@property(nonatomic, retain) NSMutableArray *equationTypes;
@property(nonatomic, retain) iSolveMathAppDelegate *data;
@end
And finally referenceViewController.m
#import "referenceViewController.h"
@implementation referenceViewController
@synthesize equationTypes, data;
data = (iSolveMathAppDelegate *)[[UIApplication sharedApplication] delegate];
//says that initializer element is not constant...ERROR!
- (void)viewDidLoad {
[super viewDidLoad];
NSString *path = [[NSBundle mainBundle] pathForResource:@"equationTemplates"ofType:@"plist"];
data.tmpArray = [[NSMutableArray alloc] initWithContentsOfFile:path];
self.equationTypes = data.tmpArray;
[data.tmpArray release]; // obviously none of these work, as data is not set.
}
- (void)dealloc {
[super dealloc];
[equationTypes release];
[data release];
}
@end
So anyway at the line data = (iSolveM开发者_运维问答athAppDelegate *)[[UIApplication sharedApplication] delegate];
the compiler says that the initializer element is not constant.
I have scrouged the web for answers, and for all it seems to work...but no dice for me :( Can you please advice me on where I have gone wrong? I am using XCode 3.2 and iOS SDK 3....maybe the SDK is the problem.
Thank You
That line of code isn't in a method or function, so the compiler is treating it as the definition of a compile-time constant or static/global variable. Those need constant values for initialization.
You should put the assignment of data
within a method. A good place would be -viewDidLoad
:
- (void)viewDidLoad {
[super viewDidLoad];
data = (iSolveMathAppDelegate *)[[UIApplication sharedApplication] delegate];
...
}
I figured out the struct and union problem. All I had to do was change @class iSolveAppDelegate
to #import "iSolveAppDelegate.h"
in my referenceViewController.h file. Thanks Jonathan for your help!
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