Camera.cs

public class Camera
{

	void TakePicture (object sender, EventArgs args)
	{
		Init ();
		picker.SourceType = UIImagePickerControllerSourceType.Camera;
		_callback = Callbak;
		PresentViewController (picker, true, null);
	}

	void Callbak (NSDictionary dic)
	{
		Console.WriteLine (dic);
		var image = dic.ObjectForKey (new NSString ("UIImagePickerControllerOriginalImage")) as UIImage;
		image.SaveToPhotosAlbum (new UIImage.SaveStatus(delegate(UIImage img, NSError error) {
			Console.WriteLine (img);	
		}));
	}

	static UIImagePickerController picker;
	static Action<NSDictionary> _callback;

	static void Init ()
	{
		if (picker != null)
			return;

		picker = new UIImagePickerController ();
		picker.Delegate = new CameraDelegate ();
	}

	class CameraDelegate : UIImagePickerControllerDelegate
	{
		public override void FinishedPickingMedia (UIImagePickerController picker, NSDictionary info)
		{
			var cb = _callback;
			_callback = null;

			picker.DismissViewController (true, null);
			cb (info);
		}
	}

}