MonoTouch MapKit 103

UPDATE 13-Oct: This code all works in the latest version of MonoTouch - v1.1 - on devices AND in the simulator. You can download a MonoDevelop solution or view the c# files:

• Main.cs
• MainWindow.xib.designer.cs

UPDATE 28-Sep:confirmation from Geoff that the problem with the Simulator should be fixed in 1.1, coming soon...

Once again thanks to a hint from Geoff, I've pieced a little more of MapKit together. This has been tested with RC2 of MonoTouch. The trick? It ONLY WORKS ON THE DEVICE - the simulator will 'crash' with the Stack Trace shown at the bottom of this post (I'm sure this will be fixed in a future release).



This code in FinishedLaunching
Once again, use the 'new' AddAnnotationObject method.

mapView.Delegate = new MapViewDelegate(this);
MyAnnotation a = new MyAnnotation(
    new CLLocationCoordinate2D(-33.867139,151.207114)
    , "Home"
   , "is where the heart is"
   );
Console.WriteLine(" ### This breaks in the simulator BUT it works on device!!!");
mapView.AddAnnotationObject(a);

with this MKAnnotation subclass
In MonoTouch MKAnnotation is an abstract class, but in ObjectiveC it's a @protocol. This kinda explains why everything in the class is read-only - @protocols are akin to interfaces in C#, but they cannot be "modelled" as interfaces in MonoTouch because @protocols members can be optional! The simplest way to get an annotation is therefore this implementation (although I think you could also create your own subclass of NSObject and Export() the MKAnnotation members manually).

public class MyAnnotation : MKAnnotation
{
   private CLLocationCoordinate2D _coordinate;
   private string _title, _subtitle;
   public override CLLocationCoordinate2D Coordinate {
      get { return _coordinate; }
   }
   public override string Title {
      get { return _title; }
   }
   public override string Subtitle {
      get { return _subtitle; }
   }
   /// <summary>
   /// Need this constructor to set the fields, since the public
   /// interface of this class is all READ-ONLY
   /// <summary>
   public MyAnnotation (CLLocationCoordinate2D coord,
                            string t, string s) : base()
   {
      _coordinate=coord;
      _title=t; 
      _subtitle=s;
   }
}

and this MKMapViewDelegate implementation

public class MapViewDelegate : MKMapViewDelegate
{
   private AppDelegate _appd;
   public MapViewDelegate (AppDelegate appd):base()
   {
      _appd = appd;
   }
   /// 

   /// When user moves the map, update lat,long text in label
   /// 
   public override void RegionChanged 
                        (MKMapView mapView, bool animated)
   {
      Console.WriteLine("Region did change");
      _appd.labelCurrent.Text = "Map Center " 
         + mapView.CenterCoordinate.Latitude + ", " 
         + mapView.CenterCoordinate.Longitude;
   }
   /// 

   /// Seems to work in the Simulator now
   /// 
   public override MKAnnotationView GetViewForAnnotation 
                    (MKMapView mapView, NSObject annotation)
   {
      var anv = mapView.DequeueReusableAnnotation("thislocation");
      if (anv == null)
      {
         Console.WriteLine("creating new MKAnnotationView");
         anv = new MKPinAnnotationView(annotation, "thislocation");
      }
      else 
      {
         anv.Annotation = annotation;
      }
      anv.AnimatesDrop = true;
      anv.PinColor = MKPinAnnotationColor.Green;
      anv.CanShowCallout = true;
      return anv;
   }
}

This Stack Trace (below) is what you'll see in MonoDevelop when using the Simulator - upload to the device to get it working (or if you are using the trial version, you may have to wait for an update to MonoTouch). UPDATE:fixed in MonoTouch 1.1

  at (wrapper managed-to-native) MonoTouch.UIKit.UIApplication.UIApplicationMain (int,string[],intptr,intptr) <0x00004>
  at (wrapper managed-to-native) MonoTouch.UIKit.UIApplication.UIApplicationMain (int,string[],intptr,intptr) 
  at MonoTouch.UIKit.UIApplication.Main (string[],string,string) 
  at MonoTouch.UIKit.UIApplication.Main (string[]) 
  at MapKit01.Application.Main (string[]) 
  at (wrapper runtime-invoke) .runtime_invoke_void_object (object,intptr,intptr,intptr) 
Native stacktrace:
 0   MapKit01          0x00092d1a mono_handle_native_sigsegv + 266
 1   MapKit01          0x00006f3a mono_sigsegv_signal_handler + 298
 2   libSystem.B.dylib 0x90b25b9b _sigtramp + 43
 3   ???               0xffffffff 0x0 + 4294967295
Debug info from gdb:
warning: Trying to remove a section from the ordered section list that did not exist at 0x2d4000.