Adding an unknown number of annotations to MKMapView

Question

So I am using the map to add points for each person that has an address in the contacts, and I am having a bit of a hard time figuring out how to set it up for the unknown number of contacts. right now the way I have it set up, it is only adding a pin for the last contact in the list. here is some code: address is a string that is set from addressProperty.

if(addressProperty != nil)
       {
           [location geocodeAddressString:address completionHandler:^(NSArray *placemarks, NSError *error) {
            NSMutableArray *array = [[NSMutableArray alloc]init];

            for(int a = 0; a < [placemarks count]; a++)
            {

               self.placeMarkData = [placemarks objectAtIndex:a];
                [point setCoordinate: self.placeMarkData.location.coordinate];

                [array addObject:point];
                pin.animatesDrop = YES;
                point.title = address;

                [map addAnnotations:array];
            }
                      }];
    }

So when I run the app I can see the pin being set in each location and moving to the next location until it ends on the last locations in the list. How can I add a point for each? I am sure it is an easy solution, but it is eluding me right now.

score 1 · Accepted Answer · answered Oct 14 '12 at 09:25

There must be a loop around all of this to be going through all the contacts. Is location a CLGeocoder? You shouldn't set two geocodeAddressString functions going on the same geocoder, you'll need to initialize a new one for each geocode your doing (unless you know for sure the previous geocode, which is asynchronous, has finished).

Four other problems:

The point variable is the same one each time. As you change the coordinate you'll that point appear in different places on the map, but it's the same one so you'll never see more than on on the map at any time.
Because it is running asynchronously you should be writing and reading a variable outside the block. Right now two geocodes could get responses at the same time and one sets self.placeMarkData just as the other one is reading the location.coordinate from it.
What is pin used for?
Don't bother adding array to the map until you've finished filling it up. If you want the points on screen asap then add them individually to the map. Adding the entire array, then adding another thing to the array and adding the entire array again is a waste.

Yeah, it is inside a loop that is getting the contacts and location is a CLGeocoder. So I would need a new geocoder for each distinct address string? And yeah, I see what you mean about the array, I just sort of missed that. Would I also need a new point object for each address? — terry lewis, Oct 14 '12 at 19:03
You need to create a new point each time you put something into the array so that you're not modifying the same one each time. And yes a new CLGeocoder for each address string is necessary but only if you're doing it in a tight loop like this. If you only did one address at a time and got a response back before sending the next one, you could use just one CLGeocoder for everything. — Craig, Oct 14 '12 at 19:25

score 0 · Answer 2 · answered Oct 14 '12 at 03:34

0

Seems like a simple bug in your code. Can you try moving the [map addAnnotations:array]; line outside of the for loop?

answered Oct 14 '12 at 03:34

abellina

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Adding an unknown number of annotations to MKMapView

2 Answers2