Converting CLLocationCoordinates2D into an NSValue

问题

I'm simply trying to convert CLLocationCoordinates into an NSValue to be used in an array brought back later in my app. Here is my code:

  NSUInteger count = [self.locations count];
    CLLocationCoordinate2D coordinates[count];
    for (NSInteger i = 0; i < count; i++) {
        coordinates[i] = [(CLLocation *)self.locations[i] coordinate];
        NSValue *locationValue = [NSValue valueWithMKCoordinate:coordinates[i]];
        [_locationsArray addObject:locationValue];
        NSLog(@"location = %@", _locationsArray);
    }

However the NSLog displays that the array is filled with (Null) values. I'm not sure where I have gone wrong here, an someone point me in the right direction?

回答1:

I didn't see any need in coordinatesarray. And you probably didn't initialised it. Try:

_locationsArray = [NSMutableArray array];
for (CLLocation *location in self.locations) {
    NSValue *locationValue = [NSValue valueWithMKCoordinate: location.coordinate];
    [_locationsArray addObject:locationValue];
    NSLog(@"location = %@", _locationsArray);
}

回答2:

Hi you can convert the CLLocationCoordinates2D into an NSValue by doing like below but have you check the coordinate contains any value or not once.

NSValue *value = [NSValue valueWithMKCoordinate:coordinate];

Thanks

回答3:

Try:

NSValue *locationValue = [NSValue valueWithBytes:&coordinates[i] objCType:@encode(CLLocationCoordinate2D)];

回答4:

It can be that you didn't initialize your array. That's why it's nil when you log it.

_locationsArray = [[NSMutableArray alloc] init];

来源：https://stackoverflow.com/questions/22113675/converting-cllocationcoordinates2d-into-an-nsvalue

标签

ios

objective-c

cllocation