windows phone 8 - location and maps
DESCRIPTION
http://winstore.vnTRANSCRIPT
Toan Huynh
Technical Evangelist
Location and Maps
Agenda
Location and
Maps on
Windows Phone 8
Introducing the new Location API
and the new Maps ControlsWindows Phone Runtime Location API
How to Get the Phone’s Current Location
How to Continuously Track the Phone’s Location
How to Run Location-Tracking Apps in the Background
Getting Started with the New Map Control
Specifying Map Center and Zoom
Animating Map Display Using Map Views
8/14/2013Microsoft confidential3
Windows Phone
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
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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
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How to Get the Phone’s Current Location
private 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 off
StatusTextBlock.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. …
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• 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 GetGeopositionAsync as 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
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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
8/14/2013
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 off
status = "location is disabled in phone settings";
break;
case PositionStatus.Initializing:
// the geolocator started the tracking operation
status = "initializing";
break;
case PositionStatus.NoData:
// the location service was not able to acquire the location
status = "no data";
break;
Geolocator Status
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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 off
status = "location is disabled in phone settings";
break;
case PositionStatus.Initializing:
// the geolocator started the tracking operation
status = "initializing";
break;
case PositionStatus.NoData:
// the location service was not able to acquire the location
status = "no data";
break;
case PositionStatus.Ready:
// the location service is generating geopositions as specified by the tracking parameters
Geolocator Status
void geolocator_PositionChanged(Geolocator sender, PositionChangedEventArgs args)
{
Dispatcher.BeginInvoke(() =>
{
LatitudeTextBlock.Text = args.Position.Coordinate.Latitude.ToString("0.00");
LongitudeTextBlock.Text = args.Position.Coordinate.Longitude.ToString("0.00");
});
}
Position Changed
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17
Demo 2
Tracking Phone Position
• 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
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• Edit WMAppManifest.xml using the XML (Text) Editor
• Replace <DefaultTask> element as shown
Enable Background Execution
19
• In App.Xaml, register an event handler for the RunningInBackground event
• 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 RunningInBackground Event
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// Static variables global to application to support tracking
public 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 location
private void Application_RunningInBackground(object sender, RunningInBackgroundEventArgs e)
{
RunningInBackground = true;
// Suspend all unnecessary processing such as UI updates
}
Implement RunningInBackground Event Handler
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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
23
Demo 3
Background Location Tracking
• 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
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private void InitializePhoneApplication()
{
...
// Handle reset requests for clearing the backstack
RootFrame.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 reset
if (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)
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private void InitializePhoneApplication()
{
...
// Handle reset requests for clearing the backstack
RootFrame.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 reset
if (e.NavigationMode == NavigationMode.Reset)
RootFrame.Navigated += ClearBackStackAfterReset;
}
private void ClearBackStackAfterReset(object sender, NavigationEventArgs e)
{
Clearing Previously Launched Pages on Fast App ResumeAdd Logic to App.Xaml.cs to Check for Reset Navigation (Behavior Already Implemented in Project Templates)
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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
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• 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 ZoomLevel properties to
change this, in XAML or in code
//Set the Map center by using Center property
MyMap.Center = new GeoCoordinate(47.6097, -122.3331);
//Set the map zoom by using ZoomLevel property
MyMap.ZoomLevel = 10;
Center and Zoom Level
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• 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
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• Set the cartographic mode of the map with the CartographicMode property
Cartographic Mode
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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
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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
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• 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 MapOverlay to a MapLayer which you
add to the Map
Pushpins
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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 Rectangle
Rectangle 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 Grid
MyGrid.Children.Add(MyRectangle);
Creating a Pushpin
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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 Rectangle
Rectangle 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 Grid
MyGrid.Children.Add(MyRectangle);
//Creating a Polygon
Creating a Pushpin
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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 it
MapLayer MyLayer = new MapLayer();
MyLayer.Add(MyOverlay);
MyMap.Layers.Add(MyLayer);
}
Drawing a UIElement onto a MapLayer
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New Maps Launchers in
Windows Phone 8.0
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
44
// 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 = new MapDownloaderTask();
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();
Review
• 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
The information herein is for informational
purposes only an represents the current view of
Microsoft Corporation as of the date of this
presentation. Because Microsoft must respond
to changing market conditions, it should not be
interpreted to be a commitment on the part of
Microsoft, and Microsoft cannot guarantee the
accuracy of any information provided after the
date of this presentation.
© 2012 Microsoft Corporation.
All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION
IN THIS PRESENTATION.