Reacting to multiple iBeacons

Question 1

Yes you can. To do that you don't have to keep property self.beaconRegion you just create as many as you like and start monitor and start ranging for it, for example this is how I do that:

//Reion 1

CLBeaconRegion *region = [[CLBeaconRegion alloc] initWithProximityUUID:uuid major:major minor:minor identifier:identifier];
region.notifyOnEntry = YES;
region.notifyOnExit = YES;
// launch app when display is turned on and inside region
region.notifyEntryStateOnDisplay = YES;

if ([CLLocationManager isMonitoringAvailableForClass:[CLBeaconRegion class]])
{
    [_locationManager startMonitoringForRegion:region];
    [_locationManager startRangingBeaconsInRegion:region];
}

//Region 2

   CLBeaconRegion *region2 = [[CLBeaconRegion alloc] initWithProximityUUID:uuid2 major:major2 minor:minor2 identifier:identifier2];
    region2.notifyOnEntry = YES;
    region2.notifyOnExit = YES;
    // launch app when display is turned on and inside region
    region2.notifyEntryStateOnDisplay = YES;

    if ([CLLocationManager isMonitoringAvailableForClass:[CLBeaconRegion class]])
    {
        [_locationManager startMonitoringForRegion:region2];
        [_locationManager startRangingBeaconsInRegion:region2];
    }

// and so on

After that in every self.locationManager delegate method make sure which beacon you have, for example:

- (void)locationManager:(CLLocationManager *)manager didEnterRegion:(CLRegion *)region {

    if ([region isKindOfClass:[CLBeaconRegion class]]) {
        CLBeaconRegion *beaconRegion = (CLBeaconRegion *)region;

        // Find out which beacon you have,
        // I check just UUID but maybe your beacons have the same uuid but major, minor are difference so you need to check minor/major as well
        if ([beaconRegion.proximityUUID isEqual:UUIDFIRST]) {

            //Do some stuff
        }
    }
}

If you want to see which beacon are nearest you use:

-(void)locationManager:(CLLocationManager *)manager didRangeBeacons:(NSArray *)beacons inRegion:(CLBeaconRegion *)region

enumerate beacons array:

if ([region isKindOfClass:[CLBeaconRegion class]]) {

        for (CLBeacon *beacon in beacons) { // 1
            // do the checking which beacon you have
            if ([beaconRegion.proximityUUID isEqual:UUIDFIRST]) { // 2

            }

                 // check beacon.accuracy property this should gives you distance in meters meters
                 //beacon.accuracy // 3
            }
        }
    }

// Extended

If you are in range two (or more) beacons the beacons are passed to you in beacons array. By calling [beacons lastObject] you get just one beacon. What you have to do is enumerate (go throughout all of the objects in array) see no 1 in my code above (I edited it a bit) and see what beacon you have (2) after that you compare the distance (3) and the one with less value is the nearest one.

Question 2

A UUID can be reused on many iBeacons. Each beacon has a major and a minor number to differentiate each one.

So a company would buy a single UUID, but (taking a store),

All majors = 1 are on the first floor:

minor 1 = to womens clothes
minor 2 = mens clothes

Major 2 = second floor:

minor 1 = kids clothes
minor 2 = footwear

... and so on. As the app walks around the store the beacons can tell it where they are and offer ad's / videos depending on the data.

You check for these values inside your didRangeBeacons callback. I also believe an app can monitor up to 20 regions at once, so the region attribute inside that callback would contain the different UUID

Question 3

The identifier provided in

[[CLBeaconRegion alloc] initWithProximityUUID:iBeacon1uuid identifier:@"com.private.Gallery"];

has to be different for each beacon you are monitoring.

In your case, they are both @"com.private.Gallery"