异常“ NSRangeException”，原因：“ ***-[__ NSArray0 objectAtIndex：]：空NSArray的索引0超出范围”

Question

usually this code has worked perfectly for me, up until recently I went to update my project to support the latest iOS and when clicking on the map button, receive the error;

Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[__NSArray0 objectAtIndex:]: index 0 beyond bounds for empty NSArray'

Prior to using Xcode 9 it would work correctly, so I am guessing the way the code works is slightly different now.

The array is NSArray *arr_OfCountryCode;

And we initialise it in the viewDidLoad

//Initialize NSArray object with Images

arr_OfCountryCode=@[@"AF",@"AL",@"DZ",@"AS",@"AD",@"AO",@"AI",@"AQ",@"AG",@"AR",@"AM",@"AW",@"AC",@"AU",@"AT",@"AZ",@"BS",@"BH",@"BD",@"BB",@"BY",@"BE",@"BZ",@"BJ",@"BM",@"BT",@"BO",@"BA",@"BW",@"BV",@"BR",@"IO",@"VG",@"BN",@"BG",@"BF",@"BI",@"KH",@"CM",@"CA",@"IC",@",CV",@"BQ",@"KY",@"CF",@"EA",@"TD",@"CL",@"CN",@"CX",@"CP",@"CC",@"CO",@"KM",@"CD",@"CG",@"CK",@"CR",@"HR",@"CU",@"CW",@"CY",@"CZ",@"CI",@"DK",@"DG",@"DJ",@"DM",@"DO",@"EC",@"EG",@"SV",@"GQ",@"ER",@"EE",@"ET",@"FK",@"FO",@"FJ",@"FI",@"FR",@"FG",@"PF",@"TF",@"GA",@"GM",@"GE",@"DE",@"GH",@"GI",@"GR",@"GL",@"GD",@"GP",@"GU",@"GT",@"GG",@"GN",@"GW",@"GY",@"HT",@"HM",@"HN",@"HK",@"HU",@"IS",@"IN",@"ID",@"IR",@"IQ",@"IE",@"IM",@"IL",@"IT",@"JM",@"JP",@"JE",@"JO",@"KZ",@"KE",@"KI",@"XK",@"KW",@"KG",@"LA",@"LV",@"LB",@"LS",@"LR",@"LY",@"LI",@"LT",@"LU",@"MO",@"MK",@"MG",@"MW",@"MY",@"MV",@"ML",@"MT",@"MH",@"MQ",@"MR",@"MU",@"YT",@"MX",@"FM",@"MD",@"MC",@"MN",@"ME",@"MS",@"MA",@"MZ",@"MM",@"NA",@"NR",@"NP",@"NL",@"NC",@"NZ",@"NI",@"NE",@"NG",@"NU",@"NF",@"KP",@"MP",@"NO",@"OM",@"PK",@"PW",@"PS",@"PA",@"PG",@"PY",@"PE",@"PH",@"PN",@"PL",@"PT",@"PR",@"QA",@"RO",@"RU",@"RW",@"RE",@"WS",@"SM",@"SA",@"SN",@"RS",@"SC",@"SL",@"SG",@"SX",@"SK",@"SI",@"SB",@"SO",@"ZA",@"GS",@"KR",@"SS",@"ES",@"LK",@"BL",@"SH",@"KN",@"LC",@"MF",@"PM",@"VC",@"SD",@"SR",@"SJ",@"SZ",@"SE",@"CH",@"SY",@"ST",@"TW",@"TJ",@"TZ",@"TH",@"TL",@"TG",@"TK",@"TO",@"TT",@"TA",@"TN",@"TR",@"TM",@"TC",@"TV",@"UM",@"VI",@"UG",@"UA",@"AE",@"GB",@"US",@"UY",@"UZ",@"VU",@"VA",@"VE",@"VN",@"WF",@"EH",@"YE",@"ZM",@"ZW",@"AX"];

When the user taps the button, a location on the map is shown at random, within the actionMethod to do that is;

str_Type = @"Randum";
        self.mapView.hidden = NO;
        int randomIndex = arc4random() % [arr_OfCountryCode count];
        NSString *urlString = [NSString stringWithFormat:@"http://maps.googleapis.com/maps/api/geocode/json?address=%@&sensor=false",[arr_OfCountryCode objectAtIndex:randomIndex]];

        NSURL *url = [[NSURL alloc] initWithString:urlString];

I am struggling as to why the array is classed as empty when it worked for multiple iOS versions and devices prior to the latest.

It is showing as nil as soon as I check it in Xcode, other arrays initialise before it with no issue, I even tried copying an existing array, renaming it to *arr_OfCountryCode; and that still showed as nil !

In this method (entire posted below) I believe the problem is occuring.

- (IBAction)actionMethod:(UIButton *)sender {
    if ([sender tag] == 0) {
        self.musicView.hidden = NO;
        [self.tbl_MusicTable reloadData];
    } else if ([sender tag] == 1) {
        str_Type = @"Randum";
        self.mapView.hidden = NO;
        int randomIndex = arc4random() % [arr_OfCountryCode count];
        NSString *urlString = [NSString stringWithFormat:@"http://maps.googleapis.com/maps/api/geocode/json?address=%@&sensor=false",[arr_OfCountryCode objectAtIndex:randomIndex]];

        NSURL *url = [[NSURL alloc] initWithString:urlString];

        [NSURLConnection sendAsynchronousRequest:[[NSURLRequest alloc] initWithURL:url] queue:[[NSOperationQueue alloc] init] completionHandler:^(NSURLResponse *response, NSData *data, NSError *error) {

            if (error) {
                NSLog(@"%@",error.description);
            } else {

                NSDictionary *jsonObject=[NSJSONSerialization
                                          JSONObjectWithData:data
                                          options:NSJSONReadingMutableLeaves
                                          error:nil];

                NSDictionary *places = [[[[jsonObject objectForKey:@"results"] objectAtIndex:0] objectForKey:@"geometry"] objectForKey:@"location"];
                NSDictionary *locations = [[[jsonObject objectForKey:@"results"] objectAtIndex:0] objectForKey:@"address_components"];

                float lat = [[places objectForKey:@"lat"] floatValue];
                float lon = [[places objectForKey:@"lng"] floatValue];

                MKCoordinateRegion region;
                MKCoordinateSpan span;
                span.latitudeDelta = 0.50;
                span.longitudeDelta = 0.50;

                location.latitude = lat;
                location.longitude = lon;
                region.span = span;
                region.center = location;
                [self.mk_MapView setRegion:region animated:YES];

                NSString *str_Title = [[locations valueForKey:@"long_name"] objectAtIndex:0];
                NSString *str_Short = [[locations valueForKey:@"short_name"] objectAtIndex:0];

                MKPointAnnotation *point = [[MKPointAnnotation alloc] init];
                point.coordinate = location;
                point.title = str_Title;
                point.subtitle = str_Short;
                [self.mk_MapView addAnnotation:point];




            }
        }];
    }
}

The further code for corelocation is here

#pragma mark - CLLocationManager Delegate Method
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
    if ([str_Type isEqualToString:@"Custom"]) {
        CLLocation *currentLocation = newLocation;
        NSString *str_Longitude;
        NSString *str_Latitude;
        MKCoordinateRegion region;
        MKCoordinateSpan span;
        span.latitudeDelta = 0.020;
        span.longitudeDelta = 0.020;
        location.latitude = currentLocation.coordinate.latitude;
        location.longitude = currentLocation.coordinate.longitude;
        region.span = span;
        region.center = location;
        [self.mk_MapView setRegion:region animated:YES];

        if (currentLocation != nil) {
            str_Longitude = [NSString stringWithFormat:@"%.8f", currentLocation.coordinate.longitude];
            str_Latitude = [NSString stringWithFormat:@"%.8f", currentLocation.coordinate.latitude];
        }

        // Reverse Geocoding
        [geocoder reverseGeocodeLocation:currentLocation completionHandler:^(NSArray *placemarks, NSError *error) {
            if (error == nil && [placemarks count] > 0) {
                placemark = [placemarks lastObject];
                MKPointAnnotation *point = [[MKPointAnnotation alloc] init];
                point.coordinate = currentLocation.coordinate;
                point.title = placemark.country;
                point.subtitle = placemark.locality;
                [self.mk_MapView addAnnotation:point];
            } else {
                NSLog(@"%@", error.debugDescription);
            }
        } ];
    } else {
        MKPointAnnotation *point = [[MKPointAnnotation alloc] init];
        point.coordinate = location;
        point.title = placemark.country;
        point.subtitle = placemark.locality;
        [self.mk_MapView addAnnotation:point];
    }
}

#pragma mark - MKMapView Delegate Methods
-(MKAnnotationView *)mapView:(MKMapView *)mV viewForAnnotation:(id <MKAnnotation>)annotation
{
    MKAnnotationView *pinView = nil;
    if(annotation != self.mk_MapView.userLocation)
    {
        static NSString *defaultPinID = @"com.invasivecode.pin";
        pinView = (MKAnnotationView *)[self.mk_MapView dequeueReusableAnnotationViewWithIdentifier:defaultPinID];
        if ( pinView == nil )
            pinView = [[MKAnnotationView alloc]
                       initWithAnnotation:annotation reuseIdentifier:defaultPinID];

        //pinView.pinColor = MKPinAnnotationColorGreen;
        pinView.canShowCallout = YES;
        //pinView.animatesDrop = YES;
        pinView.image = [UIImage imageNamed:@"HesOnThisMap"];    //
    }
    else {
        //[self.mk_MapView.userLocation setTitle:@"I am here"];
    }
    return pinView;
}

- (void)mapView:(MKMapView *)mapView didAddAnnotationViews:(NSArray *)views {
    MKAnnotationView *aV;
    for (aV in views) {
        CGRect endFrame = aV.frame;
        aV.frame = CGRectMake(aV.frame.origin.x, aV.frame.origin.y - 230.0, aV.frame.size.width, aV.frame.size.height);
        [UIView beginAnimations:nil context:NULL];
        [UIView setAnimationDuration:0.45];
        [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
        [aV setFrame:endFrame];
        [UIView commitAnimations];
    }
}

Answer 1

这与Google Maps api回调有关，当达到最大回调时崩溃