Question

I’m going crazy with this my little app… Please help me!!!

this is the source code of the app: Smoking.zip

It only saves a .dat file with an NSMutableArray.
Now, the first time you will launch the app, try to click the cigarette button sometimes: Everything should working fine.
Ok, now close the app, re-open it, and click again on the button. This time the app will crash with the “unrecognized selector sent to instance 0x5d18d60” error.
I was sure the problem was in saving the data, because when i commented the line “[theData writeToFile:dataFilePath atomically:YES];” in the “saveData” method the error disappeared.
Later i discovered that it appears again if i try to read the data from the NSMutableArray.

Please take a moment to check my project and help me, beacause i’m going crazy about that!!

Here’s some code:

#import "SmokingAppDelegate.h"
#import "SmokingViewController.h"
#import "Cig.h"

@implementation SmokingAppDelegate

@synthesize window;
@synthesize viewController, dataFilePath, smokeArray;


#pragma mark -
#pragma mark Application lifecycle

- (id) init {

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *path = [documentsDirectory stringByAppendingPathComponent:@"a.dat"];

    [self setDataFilePath:path];

    NSFileManager *fileManager = [NSFileManager defaultManager];
    if([fileManager fileExistsAtPath:dataFilePath]

       ) {
        //open it and read it 
        NSLog(@"data file found. reading into memory");

        smokeArray = [[NSMutableArray alloc] init];

        NSMutableData *theData;
        NSKeyedUnarchiver *decoder;
        NSMutableArray *tempArray;

        theData = [NSData dataWithContentsOfFile:dataFilePath];
        decoder = [[NSKeyedUnarchiver alloc] initForReadingWithData:theData];
        tempArray = [decoder decodeObjectForKey:@"smokeArray"];
        [self setSmokeArray:tempArray];

        [decoder finishDecoding];
        [decoder release];      
    } else {
        NSLog(@"no file found. creating empty array");

        smokeArray = [[NSMutableArray alloc] init];
        [smokeArray insertObject:[[NSNumber alloc] initWithInt:0] atIndex:0];

    }

//  [self logArrayContents];

    return self;
}

- (void) logArrayContents {

    for(int j = 1; j < [smokeArray count]; j++) {
        int f = [[[smokeArray objectAtIndex:j] num] intValue];
        NSLog(@"%i. - %d", j, f);
    }
}

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    

    // Override point for customization after application launch.

    // Add the view controller's view to the window and display.
    [window addSubview:viewController.view];
    [window makeKeyAndVisible];

    return YES;
}



-(void) saveData {
    NSMutableData *theData;
    NSKeyedArchiver *encoder;

    theData = [NSMutableData data];
    encoder = [[NSKeyedArchiver alloc] initForWritingWithMutableData:theData];

    [encoder encodeObject:smokeArray forKey:@"smokeArray"];

    [encoder finishEncoding];

    [theData writeToFile:dataFilePath atomically:YES];
    [encoder release];
    NSLog(@"Saved");
}

#pragma mark -
#pragma mark Memory management


- (void)dealloc {
    [viewController release];
    [window release];
    [dataFilePath release];
    [smokeArray release];
    [super dealloc];
}


@end



#import "SmokingViewController.h"
#import "SmokingAppDelegate.h"
#import "Cig.h"

@implementation SmokingViewController
@synthesize label;

- (void)viewDidLoad {
[super viewDidLoad];

    SmokingAppDelegate *mainDelegate = (SmokingAppDelegate *)[[UIApplication sharedApplication] delegate];

//controlla se il giorno è lo stesso rispetto a quello dell'ultima sigaretta fumata
    if ([mainDelegate.smokeArray count] > 1) {


        Cig *oldCig = [mainDelegate.smokeArray lastObject];
        NSArray *tempArray = [self quando];

        if (    [[tempArray objectAtIndex:0] intValue]==[[oldCig.dat objectAtIndex:0] intValue]
            &&  [[tempArray objectAtIndex:1] intValue]==[[oldCig.dat objectAtIndex:1] intValue]
            &&  [[tempArray objectAtIndex:2] intValue]==[[oldCig.dat objectAtIndex:2] intValue]
            ) {
            N = [oldCig.num intValue];
        }
        else {
            N = 0;
        }

        [oldCig release];
        [tempArray release];

 }


//scrive quante sigarette si sono fumate oggi
    label.text = [NSString stringWithFormat: @"Today you smoked %d cigarettes",N];




}

- (IBAction) smoke:(UIButton * ) button {

    SmokingAppDelegate *mainDelegate = (SmokingAppDelegate *)[[UIApplication sharedApplication] delegate];
    NSLog(@"L'array contiene %d sigarette", [mainDelegate.smokeArray count]-1);

    N += 1;

    [self addNewCigToArray];
    [mainDelegate logArrayContents];
    [mainDelegate saveData];

    label.text = [NSString stringWithFormat: @"Today you smoked %d cigarettes",N];


}


- (void) addNewCigToArray {

    //NSLog(@"new cigarette smoked");
    SmokingAppDelegate *mainDelegate = (SmokingAppDelegate *)[[UIApplication sharedApplication] delegate];
    Cig *newCig = [[Cig alloc] init]; 

    [newCig setDat:[self quando]]; 
    [newCig setNum:[[NSNumber alloc] initWithInt:N]];

    [mainDelegate.smokeArray addObject:newCig]; 
    [newCig release];
    //[mainDelegate logArrayContents];

}

- (NSArray *) quando {

    NSDateFormatter *timeFormat = [[NSDateFormatter alloc] init];   

    // 0 - Year
    [timeFormat setDateFormat:@"YYYY"];
    NSString *year = [timeFormat stringFromDate:[NSDate date]];

    // 1 - Month
    [timeFormat setDateFormat:@"MM"];
    NSString *month = [timeFormat stringFromDate:[NSDate date]];

    // 2 - Day
    [timeFormat setDateFormat:@"dd"];
    NSString *day = [timeFormat stringFromDate:[NSDate date]];

    // 3 - Hour 
    [timeFormat setDateFormat:@"HH"];
    NSString *hour = [timeFormat stringFromDate:[NSDate date]];

    // 4 - Minute
    [timeFormat setDateFormat:@"mm"];
    NSString *min = [timeFormat stringFromDate:[NSDate date]];

    // 5 - Second
    [timeFormat setDateFormat:@"ss"];
    NSString *sec = [timeFormat stringFromDate:[NSDate date]];

    NSArray *newArray = [[NSArray alloc] initWithObjects:year,month,day,hour,min,sec,nil];

    return newArray;

}


- (void)viewDidUnload {
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
}


- (void)dealloc {
    [super dealloc];
}

@end

Answer 1

Okay, I am an iPhone newbie so take my suggestion in stride. You could try creating an NSData object, initializing it with theData, and then calling writeToFile on the new NSData object instead of the NSMutableData object.