Send Files through AirDrop using Xamarin.iOS

Sending Files

AirDrop has been baked into the UIActivityViewController. All that’s needed to send a file via AirDrop is to pass it in as an item in a NSObject Array to the first parameter of the UIActivityViewController.

In the following example we create an UIImageView that takes up the entire screen. A button is also added to the view. On the click event of the button we present a new UIActivityViewController, whose constructor has a one item NSObject array that contains the UIImageViews Image.

        public override void ViewDidLoad()
        {
            base.ViewDidLoad();

            var bounds = UIScreen.MainScreen.Bounds;

            //Initialize ImageView and set it as a 'background'
            _imageView = new UIImageView(bounds) {Image = UIImage.FromFile("IMG_5398.JPG")};
            _imageView.Image.Scale(bounds.Size);
            Add(_imageView);

            _button = UIButton.FromType(UIButtonType.RoundedRect);

            //Place button in the middle
            _button.Frame = new RectangleF(
                View.Frame.Width / 2 - ButtonWidth / 2,
                View.Frame.Height / 2 - ButtonHeight / 2,
                ButtonWidth,
                ButtonHeight);
            _button.BackgroundColor = UIColor.White;

            _button.SetTitle("Click me", UIControlState.Normal);

            _button.TouchUpInside += (sender, e) =>
            {
                //This constructor will give us the option to share the _imageView.Image via AirDrop
                var a = new UIActivityViewController(new NSObject[] { _imageView.Image }, null);
                PresentViewController(a, true, null);
            };

            _button.AutoresizingMask = UIViewAutoresizing.FlexibleWidth | UIViewAutoresizing.FlexibleTopMargin |
                UIViewAutoresizing.FlexibleBottomMargin;

            View.AddSubview(_button);
        }

That’s it! The source code to the recipe is available on GitHub.

Xamarin iOS 7 MapKit MKDirections

Greetings! In the post we’ll cover using the MKDirections class to retrieve direction related information from Apple. We’ll then use those directions to draw a route on the map. The source code can be found on GitHub

First, we need the following namespaces

using MonoTouch.MapKit;
using MonoTouch.CoreLocation;

Next, we’ll add an MKMapView instance variable, and a MPMapViewDelegate.

        private MKMapView _map;
        private MKMapViewDelegate _mapDelegate;

In the ViewController’s ViewDidLoad method we will initialize the map, the map delegate, and call a method to get directions and create a route.

        public override void ViewDidLoad()        {
            base.ViewDidLoad();

            //Init Map
            _map = new MKMapView
            {
                MapType = MKMapType.Standard,
                ShowsUserLocation = true,
                ZoomEnabled = true,
                ScrollEnabled = true
            };

            //Create new MapDelegate Instance
            _mapDelegate = new MapDelegate();

            //Add delegate to map
            _map.Delegate = _mapDelegate;

            View = _map;

            //Create Directions
            CreateRoute();
        }

The CreateRoute function is where the magic happens…

We’ll need to crate two MKPlaceMarks, one for the source and one for the destination. These are used to create two MKMapItems that are used when making the directions request.

            //Create Origin and Dest Place Marks and Map Items to use for directions
            //Start at Xamarin SF Office
            var orignPlaceMark = new MKPlacemark(new CLLocationCoordinate2D(37.797530, -122.402590), null);
            var sourceItem = new MKMapItem(orignPlaceMark);

            //End at Xamarin Cambridge Office
            var destPlaceMark = new MKPlacemark(new CLLocationCoordinate2D(42.374172, -71.120639), null);
            var destItem = new MKMapItem(destPlaceMark);

Next, we’ll need to create a request for directions using MKDirectionsRequest using the the source and dest items above, and pass these to a new instance of MKDirections.

            var request = new MKDirectionsRequest
            {
                Source = sourceItem,
                Destination = destItem,
                RequestsAlternateRoutes = true
            };

            var directions = new MKDirections(request);

Next, we need to make the call to get the directions. When the directions are returned, we’ll loop through the collections of routes and add the PolyLine from each route to our map overlay collection.

            directions.CalculateDirections((response, error) =>
            {
                if (error != null)
                {
                    Console.WriteLine(error.LocalizedDescription);
                }
                else
                {
                   //Add each Polyline from route to map as overlay
                    foreach (var route in response.Routes)
                    {
                        _map.AddOverlay(route.Polyline);
                    }
                }
            });

Remember the _mapDelegate we create earlier? This is actually a class that inherits from MKMapViewDelegate. We need to override the OverlayRenderer in order to actually draw the route on the map.

  class MapDelegate : MKMapViewDelegate
  {
        //Override OverLayRenderer to draw Polyline from directions
        public override MKOverlayRenderer OverlayRenderer(MKMapView mapView, IMKOverlay overlay)
            {
                if (overlay is MKPolyline)
                {
                    var route = (MKPolyline)overlay;
                    var renderer = new MKPolylineRenderer(route) { StrokeColor = UIColor.Blue };
                    return renderer;
                }
                return null;
            }
        }

    }

That’s it! When we put it all together we end up with the map below.

iOS 7 Directions

InauguralBlog Post

Welcome to my blog! If you’re here you probably already know this, but my name is Blake Davidson. I am glad you decided to stop by and hang out! I plan to use this space to share various projects and coding endeavors. Please feel free to send me an e-mail at davidsonblake86@gmail.com, or look me up on twitter @davidsonblake86.