Question

In this method I add the content of UITextFields, images and other strings in a sqlite database. Everything works fine. I mean, when i press the “Add” button, the “OK” image appear, the sound play and all the contents are added to the database (I can check restarting the application). But after all of this, I have this error in the “main.m”

This is the method:

-(IBAction)addItem:(id)sender { //gestione pulsante aggiunta elemento
    if (([itemNameField.text length] == 0) || ([priceField.text length] == 0) || ([priceField.text doubleValue] == 0.0) || ((incomeOutcome.selectedSegmentIndex != 0) && (incomeOutcome.selectedSegmentIndex != 1))) {
        if ([itemNameField.text length] == 0) {
        statusLabel.text = [[NSString alloc] initWithFormat: @"Specificare un nome."];
        } else if (([priceField.text length] == 0) || ([priceField.text doubleValue] == 0.0)) {
            statusLabel.text = [[NSString alloc] initWithFormat: @"Specificare un prezzo."];
        } else if ((incomeOutcome.selectedSegmentIndex != 0) && (incomeOutcome.selectedSegmentIndex != 1)) {
            statusLabel.text = [[NSString alloc] initWithFormat: @"Specificare \"Income/Outcome\" ."];            
        }
        if (!categoriaLabel.hidden) {
            [self hideThemAll];
        }
        [incomeOutcome setSelectedSegmentIndex:-1];
        statusLabel.hidden = NO;
        error = true;
        [self playSound];
        [ok setImage:[UIImage imageNamed:@"error.png"]];
        ok.hidden = NO;
        return;
    }
    //apriamo il database
    sqlite3 *db;
    int dbrc; //Codice di ritorno del database (database return code)
    iWalletAppDelegate *appDelegate = (iWalletAppDelegate*) [UIApplication sharedApplication].delegate;
    const char *dbFilePathUTF8 = [appDelegate.dbFilePath UTF8String];
    dbrc = sqlite3_open(dbFilePathUTF8, &db);
    if (dbrc) {
        NSLog(@"Impossibile aprire il Database!");
        return;
    }
    //database aperto! Inseriamo valori nel database.
    sqlite3_stmt *dbps; //Istruzione di preparazione del database
    NSString *insertStatementsNS;
    if (incomeOutcome.selectedSegmentIndex == 0) {
        insertStatementsNS = [NSString stringWithFormat: @"insert into \"shoppinglist\" (item, price, groupid, incout, path,  dateadded) values (\"%@\", \"%@\", \"Entrata\", %d, \"%@\", DATETIME('NOW'))", itemNameField.text, priceField.text, incomeOutcome.selectedSegmentIndex, imagePath];
    } else if ([categoryNameField.text length] != 0) { 
        insertStatementsNS = [NSString stringWithFormat: @"insert into \"shoppinglist\" (item, price, groupid, incout, path, dateadded) values (\"%@\", \"%@\", \"%@\", %d, \"%@\", DATETIME('NOW'))", itemNameField.text, priceField.text, categoryNameField.text, incomeOutcome.selectedSegmentIndex, imagePath]; 
    } else { 
        insertStatementsNS = [NSString stringWithFormat: @"insert into \"shoppinglist\" (item, price, groupid, incout, path, dateadded) values (\"%@\", \"%@\", \"Varie\", %d, \"%@\", DATETIME('NOW'))", itemNameField.text, priceField.text, incomeOutcome.selectedSegmentIndex, imagePath];
    }
    const char *insertStatement = [insertStatementsNS UTF8String];
    dbrc = sqlite3_prepare_v2(db, insertStatement, -1, &dbps, NULL);
    dbrc = sqlite3_step(dbps);

    //faccio pulizia rilasciando i database
    sqlite3_finalize(dbps);
    sqlite3_close(db);

    // Pulisci i campi e indica successo nello status
    statusLabel.hidden = NO;
    statusLabel.text = [[NSString alloc] initWithFormat: @"Aggiunto %@", itemNameField.text];

    itemNameField.text = @"";
    priceField.text = @"";
    categoryNameField.text = @"";
    imagePath = @"";
    [incomeOutcome setSelectedSegmentIndex:-1];
    error = false;
    [self hideThemAll];
    [self playSound];
    [ok setImage:[UIImage imageNamed:@"ok.png"]];
    ok.hidden = NO;
    nome = @"";
    prezzo =@"";
    [photoPreview setImage:[UIImage imageNamed:@"noPhoto.png"]];
    [[self parentViewController]dismissModalViewControllerAnimated:YES];
}    

EDIT

Thanks to Isaac I (maybe) found the issue: I wasn’t retaining the picture I took from the camera.

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
    [picker dismissModalViewControllerAnimated:YES];
    int r = arc4random() % 9999;
    NSDate *date = [NSDate date];
    NSString *photoName = [dateNameFormatter stringFromDate:date];
    photoName = [photoName stringByAppendingString:[NSString stringWithFormat:@"%d", r]];

    if (imagePath) {
        [imagePath release];
    }
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    imagePath = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.png", photoName]];
    [imagePath retain];

    UIImage *picture = [info objectForKey:UIImagePickerControllerOriginalImage];

    // ----- CODE FOR SCALE THE IMAGE ----- //
    if (picture.size.width == 1936) {
        picture = [picture scaleToSize:CGSizeMake(480.0f, 720.0f)];
    } else {
        picture = [picture scaleToSize:CGSizeMake(720.0f, 480.0f)];
    }

    photoPreview.image =  picture;

    photoPreview.contentMode = UIViewContentModeScaleAspectFit;

    CGRect frame = photoPreview.frame;
    if (picture.size.width == 480) {
        frame.size.width = 111.3;
        frame.size.height =167;
    } else {
        frame.size.width = 167;
        frame.size.height =111.3;
    }
    photoPreview.frame = frame;
    // ----- ----- - END CODE - ----- ----- //    

    NSData *webData = UIImagePNGRepresentation(picture);
    CGImageRelease([picture CGImage]);
    [webData writeToFile:imagePath atomically:YES];
    [picture retain]; // <-- This little thing here!
    //imgPicker = nil;
}

Now it works! But if you can see other problems, please let me notice them.

Answer 1

Typically an EXC_BAD_ACCESS occurs when you are trying to access memory that has been deallocated. In your code sample, I don’t see any [object release] calls (that’s another problem entirely, unless you happen to be using ARC). But my guess it that this error is the result of a call that is being made outside of the scope of this method – something is being released prematurely.

You could paste your entire class, or, consider using the Instruments tool ‘Zombies’ to identify the dangling pointer which is (probably) causing this.