Location and Maps

Nguyen Tuan | Microsoft Certified Trainer

Agenda

Runtime Location API

Current Location

How to Continuously Track the Phone’s Location

How to Run Location-Tracking Apps in the Background

How to use Map Control

Specifying Map Center and Zoom

Animating Map Display Using Map Views

8/16/2014 3

WP Runtime Location API

Location APIs on Windows Phone 8

• .NET Location API from Windows Phone OS 7.1 is still supported

• System.Device.Location.GeoCoordinateWatcher and related classes

• New Windows Phone Runtime location API• Accessible from managed and native code

• Improved ability for one-shot location acquisition

• Improved capabilities for location tracking

• Convergent with Windows 8 location API

ID_CAP_LOCATION Capability

• You must include the ID_CAP_LOCATION capability in your app manifest

• If you forget, calls to location APIs throw an UnauthorizedAccessException

8/16/2014 5

Location Sources

Location Services

+ Accuracy- Power- Speed- Indoors

- Accuracy+ Power+ Speed- Wilderness

+/- Accuracy+/- Power+/- Speed+/- Urban areas

GPS

Cell Towers

WiFi

• You can’t!

• You can set the DesiredAccuracy property of the Geolocator object:• PositionAccuracy.High – if you want the most accurate data available, but at the cost of increased

battery usage, network bandwidth and possibly monetary charges from wireless network operators. Often this causes the GPS to be activated

• PositionAccuracy.Default – to optimize for power

• You can also set the DesiredAccuracyInMeters property to indicate to the Geolocation service the desired accuracy of any results

• However, the Geolocation service determines the best location data to provide to the application

Controlling the Sources the Geolocation Service Uses

8/16/2014 ‹#›

How to Get the Phone’s Current Locationprivate async void OneShotLocation_Click(object sender, RoutedEventArgs e){

Geolocator geolocator = new Geolocator();geolocator.DesiredAccuracyInMeters = 50;try{

Geoposition geoposition = await geolocator.GetGeopositionAsync(maximumAge: TimeSpan.FromMinutes(5),timeout: TimeSpan.FromSeconds(10));

LatitudeTextBlock.Text = geoposition.Coordinate.Latitude.ToString("0.00");LongitudeTextBlock.Text = geoposition.Coordinate.Longitude.ToString("0.00");

}catch (UnauthorizedAccessException){

// the app does not have the right capability or the location master switch is offStatusTextBlock.Text = "location is disabled in phone settings.";

}}

User Consent

• Application certification requirements on user consent still the same as in 7.1

• If you are using location data just within your app, you do not need to ask explicitly for user consent (although they give consent when they install your app)

• You only have to get user consent if you plan to make location data available to any other service or other person:

2.7.4 If your application publishes or makes available location data obtained from the Location Service API to any other service or other person (including advertising networks), your application must implement a method to obtain opt-in consent. …

8/16/2014 9

• Windows Phone Emulator comes with Location simulator

Location on Emulator

10

• If your app only needs the user’s location at the current time, use GetGeopositionAsyncas already described

• Continuously tracking the user’s location drains the user’s battery more and should only be used for apps that require it

Location Tracking

8/16/2014 11

private void TrackLocation_Click(object sender, RoutedEventArgs e){

if (!tracking) {geolocator = new Geolocator();geolocator.DesiredAccuracy = PositionAccuracy.High;geolocator.MovementThreshold = 100; // The units are meters.geolocator.StatusChanged += geolocator_StatusChanged;geolocator.PositionChanged += geolocator_PositionChanged;tracking = true;

}else {

geolocator.PositionChanged -= geolocator_PositionChanged;geolocator.StatusChanged -= geolocator_StatusChanged;geolocator = null;tracking = false;

}}

How to Track Location

8/16/2014

void geolocator_StatusChanged(Geolocator sender, StatusChangedEventArgs args){

string status = "";switch (args.Status){

case PositionStatus.Disabled:// the application does not have the right capability or the location master switch is offstatus = "location is disabled in phone settings";break;

case PositionStatus.Initializing:// the geolocator started the tracking operationstatus = "initializing";break;

case PositionStatus.NoData:// the location service was not able to acquire the locationstatus = "no data";break;

Geolocator Status

8/16/2014 13

void geolocator_StatusChanged(Geolocator sender, StatusChangedEventArgs args){

string status = "";switch (args.Status){

case PositionStatus.Disabled:// the application does not have the right capability or the location master

switch is offstatus = "location is disabled in phone settings";break;

case PositionStatus.Initializing:// the geolocator started the tracking operationstatus = "initializing";break;

case PositionStatus.NoData:// the location service was not able to acquire the locationstatus = "no data";break;

case PositionStatus.Ready:// the location service is generating geopositions as specified by the

tracking parametersstatus = "ready";

Geolocator Status

void geolocator_PositionChanged(Geolocator sender, PositionChangedEventArgsargs){

Dispatcher.BeginInvoke(() =>{

LatitudeTextBlock.Text = args.Position.Coordinate.Latitude.ToString("0.00");

LongitudeTextBlock.Text = args.Position.Coordinate.Longitude.ToString("0.00");

});}

Position Changed

8/16/2014 15

Demo LocationTracker

16

• Normally, when your user navigates away from your app, it is made dormant and all activity – including location tracking – is suspended

• In Windows Phone 8, a location-tracking app can continue to run in the background after the user navigates away, as long as the app continues to actively track location

• This feature enables scenarios such as an app that provides turn-by-turn directions or a run tracker

Enable Location Tracking in the Background

8/16/2014 17

• Edit WMAppManifest.xml using the XML (Text) Editor• Replace <DefaultTask> element as shown

Enable Background Execution

18

• In App.Xaml, register an event handler for the RunningInBackgroundevent

• This event is raised when the user navigates away from your background execution-enabled app while you are actively tracking location

• When this event is raised, your app should stop all tasks that are not related to location tracking, including updates to the app’s UI

<Application.ApplicationLifetimeObjects><!--Required object that handles lifetime events for the application--><shell:PhoneApplicationService

Launching="Application_Launching" Closing="Application_Closing“Activated="Application_Activated" Deactivated="Application_Deactivated“RunningInBackground="Application_RunningInBackground"/></Application.ApplicationLifetimeObjects>

Register Event Handler for RunningInBackgroundEvent

8/16/2014 19

// Static variables global to application to support trackingpublic static Geolocator Geolocator { get; set; }public static bool RunningInBackground { get; set; }

// Code to execute when the application is activated (brought to foreground)private void Application_Activated(object sender, ActivatedEventArgs e){

RunningInBackground = false;}

// Code to execute when the application is deactivated and is tracking locationprivate void Application_RunningInBackground(object sender, RunningInBackgroundEventArgs e){

RunningInBackground = true;// Suspend all unnecessary processing such as UI updates

}

Implement RunningInBackground Event Handler

8/16/2014 20

void geolocator_PositionChanged(Geolocator sender, PositionChangedEventArgs args){

if (!App.RunningInBackground){

Dispatcher.BeginInvoke(() => {LatitudeTextBlock.Text = args.Position.Coordinate.Latitude.ToString("0.00");LongitudeTextBlock.Text = args.Position.Coordinate.Longitude.ToString("0.00"); });

}else{ // DEMO purposes only: Show toast if running in background

Microsoft.Phone.Shell.ShellToast toast = new Microsoft.Phone.Shell.ShellToast();toast.Content = args.Position.Coordinate.Latitude.ToString("0.00");toast.Title = "Location: ";toast.NavigationUri = new Uri("/Page2.xaml", UriKind.Relative);toast.Show();

}}

Do Not Update UI When Running in the BackgroundExample

• As we have seen, Background Location Tracking apps continue to run in the background

• But if it is not actively tracking location when deactivated, it is made dormant as normal• If the user launches *another* location tracking app and deactivates that, then your app will be made dormant

• If the user launches a new instance of the app, if there is a dormant instance, that is reactivated instead

• Background Location Tracking apps get the Fast Application Resume behavior, which reactivates a dormant application if the user launches a new copy

• The dormant instance of the app, including the history of visited app pages, is reactivated

• By default, the list of previously visited pages is cleared for these ‘Reset’ activations

• This may not be what you want…

App Lifecycle for Background Location Tracking AppsFast Application Resume

8/16/2014 22

private void InitializePhoneApplication(){

...// Handle reset requests for clearing the backstackRootFrame.Navigated += CheckForResetNavigation;

...}

private void CheckForResetNavigation(object sender, NavigationEventArgs e){

// If the app has received a 'reset' navigation, then we need to check// on the next navigation to see if the page stack should be resetif (e.NavigationMode == NavigationMode.Reset)

RootFrame.Navigated += ClearBackStackAfterReset;}

Clearing Previously Launched Pages on Fast App ResumeAdd Logic to App.Xaml.cs to Check for Reset Navigation (Behavior Already Implemented in Project Templates)

8/16/2014 23

private void InitializePhoneApplication(){

...// Handle reset requests for clearing the backstackRootFrame.Navigated += CheckForResetNavigation;

...}

private void CheckForResetNavigation(object sender, NavigationEventArgs e){

// If the app has received a 'reset' navigation, then we need to check// on the next navigation to see if the page stack should be resetif (e.NavigationMode == NavigationMode.Reset)

RootFrame.Navigated += ClearBackStackAfterReset;}

private void ClearBackStackAfterReset(object sender, NavigationEventArgs e){

// Unregister the event so it doesn't get called againRootFrame.Navigated -= ClearBackStackAfterReset;// Only clear the stack for 'new' (forward) and 'refresh' navigationsif (e.NavigationMode != NavigationMode.New && e.NavigationMode != NavigationMode.Refresh)

return;// For UI consistency, clear the entire page stackwhile (RootFrame.RemoveBackEntry() != null) { } // do nothing

}

Clearing Previously Launched Pages on Fast App ResumeAdd Logic to App.Xaml.cs to Check for Reset Navigation (Behavior Already Implemented in Project Templates)

8/16/2014 24

DemoBackgroundLocationTracker

Maps

Maps APIs on Windows Phone 8

• Windows Phone 8 has new Map controls, accessible in the following namespaces:

• Microsoft.Phone.Maps• Microsoft.Phone.Maps.Controls• Microsoft.Phone.Maps.Services

• The Bing Maps Control is still supported, but is deprecated

• You should only use the Bing Maps Control when you upgrade an app from Windows Phone OS 7.1 to Windows Phone 8

• Usage of the new Maps control differs from the Bing Maps control

ID_CAP_MAP Capability

• You must include the ID_CAP_MAP capability in your app manifest

• If you forget, calls to location APIs throw an UnauthorizedAccessException

8/16/2014 28

• Add a Map to your UI• In XAML:

<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0"><maps:Map x:Name="MyMap"/>

</Grid>

• In Code:private void CreateMap(){

Map MyMap = new Map();ContentPanel.Children.Add(MyMap);

}

Map Control

• By default, map displays at zoom level 1 (world view) and centered at Lat: 0, Long: 0

• Use the Center and ZoomLevelproperties to change this, in XAML or in code

//Set the Map center by using Center propertyMyMap.Center = new GeoCoordinate(47.6097, -

122.3331);

//Set the map zoom by using ZoomLevel propertyMyMap.ZoomLevel = 10;

Center and Zoom Level

8/16/2014 30

• It is common to move a map display from one location to another

• A new map view is defined any time the position of the map is changed as a result of panning, zooming, rotating, or tilting

• You can use the SetView method to define a map view. This takes the following parameters:

• Center: A GeoCoordiante object defining the center of the map view

• ZoomLevel: zoom level between 1 and 20

• Heading: specifies the directional heading that is pointing “up” on the mapin geometric degrees between 0 and 360

• Pitch: specifies the degree to which the map is tilted as a value between 0 and 180

• BoundingRectangle: a LocationRectangle object that contains the Map control

• AnimationKind: sets the kind of animation you want to see (None, Linear or Parabolic) when the view changes

MapViews

8/16/2014 31

• Set the cartographic mode of the map with the CartographicModeproperty

Cartographic Mode

8/16/2014 32

Road (default) Aerial Hybrid Terrain

• You can display the map in a light or dark color mode by setting the ColorMode property

Light and Dark Color Modes

8/16/2014 33

Light (default) Dark

• You can display additional elements on your map, such as landmarks and pedestrian features

• Set the LandmarksEnabled property to true to display landmarks

• Set the PedestrianFeaturesEnabled to true to display pedestrian features

• Landmarks are visible only when the ZoomLevel is 7 or higher, and the Pitch property is 25 or higher

Pedestrian Features and Landmarks

8/16/2014 34

Demo 1. BasicLocationandMap2. MapViews

35

• Unlike the Bing Maps API, the Windows Phone Maps API does not have a specific PushPin object

• However, you can create your own PushPins by drawing UIElements onto a MapOverlay, then add the MapOverlayto a MapLayer which you add to the Map

Pushpins

8/16/2014 36

private Grid CreatePushpin(){

//Creating a Grid element.Grid MyGrid = new Grid();MyGrid.RowDefinitions.Add(new RowDefinition());MyGrid.RowDefinitions.Add(new RowDefinition());MyGrid.Background = new SolidColorBrush(Colors.Transparent);//Creating a RectangleRectangle MyRectangle = new Rectangle();MyRectangle.Fill = new SolidColorBrush(Colors.Black);MyRectangle.Height = 20;MyRectangle.Width = 20;MyRectangle.SetValue(Grid.RowProperty, 0);MyRectangle.SetValue(Grid.ColumnProperty, 0);//Adding the Rectangle to the GridMyGrid.Children.Add(MyRectangle);

Creating a Pushpin

8/16/2014 37

private Grid CreatePushpin(){

//Creating a Grid element.Grid MyGrid = new Grid();MyGrid.RowDefinitions.Add(new RowDefinition());MyGrid.RowDefinitions.Add(new RowDefinition());MyGrid.Background = new SolidColorBrush(Colors.Transparent);//Creating a RectangleRectangle MyRectangle = new Rectangle();MyRectangle.Fill = new SolidColorBrush(Colors.Black);MyRectangle.Height = 20;MyRectangle.Width = 20;MyRectangle.SetValue(Grid.RowProperty, 0);MyRectangle.SetValue(Grid.ColumnProperty, 0);//Adding the Rectangle to the GridMyGrid.Children.Add(MyRectangle);

//Creating a Polygon

Creating a Pushpin

8/16/2014 38

private void AddMapOverlay(){

Grid MyGrid = CreatePushpin();

//Creating a MapOverlay and adding the Grid to it.MapOverlay MyOverlay = new MapOverlay();MyOverlay.Content = MyGrid;MyOverlay.GeoCoordinate = new GeoCoordinate(47.6097, -122.3331);MyOverlay.PositionOrigin = new Point(0, 0.5);

//Creating a MapLayer and adding the MapOverlay to itMapLayer MyLayer = new MapLayer();MyLayer.Add(MyOverlay);MyMap.Layers.Add(MyLayer);

}

Drawing a UIElement onto a MapLayer

8/16/2014 39

DemoLocationAndMaps

40

Maps Launchers

MapsTaskMapsTask makes launching the built-in Maps application easy

MapsTask mapsTask = new MapsTask();

//Omit the Center property to use the user's current location.mapsTask.Center = new GeoCoordinate(47.6204, -122.3493);

mapsTask.SearchTerm = "coffee";mapsTask.ZoomLevel = 17;

mapsTask.Show();

• Launching built-in Maps tasks with directions enabled is trivial too!

MapsDirectionsTask

43

// Get DirectionsMapsDirectionsTask mapsDirectionsTask = new MapsDirectionsTask();

// You can specify a label and a geocoordinate for the end point.// GeoCoordinate spaceNeedleLocation = new GeoCoordinate(47.6204,-122.3493);// LabeledMapLocation spaceNdleLML = new LabeledMapLocation("Space Needle", spaceNeedleLocation);

// If you set the geocoordinate parameter to null, the label parameter// is used as a search term.LabeledMapLocation spaceNdleLML = new LabeledMapLocation("Space Needle", null);

// If mapsDirectionsTask.Start is not set, the user's current location// is used as start point.mapsDirectionsTask.End = spaceNdleLML;mapsDirectionsTask.Show();

• Use the map downloader task to enable users to download map data for offline use

• The task launches the Maps settings application which allows the user to select a region of map data to download

MapDownloaderTask

MapDownloaderTask mapDownloaderTask = newMapDownloaderTask();

mapDownloaderTask.Show();

• Use the map updater task to enable users to update map data they have previously downloaded for offline use

• The task launches the Maps settings application which immediately checks to see if there are updates available for any previously downloaded map data

MapUpdaterTask

MapUpdaterTask mapUpdaterTask = new MapUpdaterTask();

mapUpdaterTask.Show();

Demo MapsTask

46

Summaries

• Windows Phone Runtime location API is new in Windows Phone 8. It has the following features:

• Accessible from managed and native code

• Greater support for one-shot location acquisition

• Support for Background Location Tracking

• Convergent with Windows 8

• Use the new Maps APIs in Windows Phone 8 to develop maps-based apps, and incorporate location and search features

• Set Center and Zoom Level

• Animate to new location and zoom using map views

• Select Road, Aerial, Hybrid or Terrain cartographic display modes

• Draw UIElements onto a MapOverlay on top of the Map