iPad Application Development For Dummies, 3rd Edition

Changing the Map Type

MapKit supports the three Map types you see on Google maps — standard, satellite, and hybrid.

The Map type is a Map View property and is represented as an enumerated type, which I have cleverly made the segment numbers in the segmented control correspond to:

enum {

MKMapTypeStandard,

MKMapTypeSatellite,

MKMapTypeHybrid

};

Add the code in bold in Listing 17-8 to the mapType: method stub that was created when you added the action in Interface Builder. The code ensures that, when the user selects a new value in the segmented control, it will change the Map type based on the selection.

Listing 17-8: Updating mapType:

- (IBAction)mapType:(id)sender {

mapView.mapType =

((UISegmentedControl *)sender).selectedSegmentIndex;

}

When the user selects a segment in the segmented control, a value-changed event is generated. This is the event (Value Changed) that you specified when you created the action in Step 4 in the “Setting up the MapController in the MainStoryboard” section, earlier in this chapter.

The segmented control has a selectedSegmentIndex property, which contains the value of the selected segment.

I had to do a cast here because the sender is of type id — a pointer to an object — which doesn’t have a selectedSegmentIndex property.

Notice that the text is white — pretty plain vanilla, if you know what I mean. To change the text to something more spring-like — a nice green, in other words — add the code in bold in Listing 17-9 to application:didFinish ...