Chapter 6

thepianoguy · March 15th, 2011, 12:53 PM

The LocalNamedNotification project presents a conflict between the colors for the background, with the appDelegate coding for red and blue and the .xib and controller files going with black and white. Easy to catch but obviously they need to match.

Also a style preference - I like setting global variables for the user defined notification constants to take advantage of autofill, and to prevent mistyping the notification name (can't imagine who would do that! I think I have a built in routine [self mistypeNotificationName];)

This is what I did, adding a prefix from the title of the program:

In the â¦Controller.h file

Code:

#import <UIKit/UIKit.h>


extern NSString * const  LNNSetImageBackgroundRed;
extern NSString * const  LNNSetImageBackgroundBlue;


@interface LocalNamedNotification_iPhoneViewController : UIViewController {

and in the â¦Controller.m file

Code:

#import "LocalNamedNotification_iPhoneViewController.h"


NSString * const  LNNSetImageBackgroundRed = @"setImageBackgroundRed";
NSString * const  LNNSetImageBackgroundBlue = @"setImageBackgroundBlue";

@implementation LocalNamedNotification_iPhoneViewController

so in the â¦AppDelegate.m file the registration would be

Code:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // Override point for customization after application launch.
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(setImageBackgroundRed:)
                                                 name:LNNSetImageBackgroundRed
                                               object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(setImageBackgroundBlue:)
                                                 name:LNNSetImageBackgroundBlue
                                               object:nil];
    
    self.window.rootViewController = self.viewController;
    [self.window makeKeyAndVisible];
    return YES;
}

with the string constant used consistently for the notification name in all other relevant places.

Bob

gbacklin · March 15th, 2011, 01:41 PM

Hey Bob,

They originally matched, then at the end in Author Review, it was brought to my attention that the book was not going to be in color, so I have to change to black and white.