URI associations for Windows Phone 8
This article explains how to associate your application with an URI scheme in order to launch it when interaction with such URI is detected.
Windows Phone 8 introduces the possibility for your app to register to a predefined kind of URI scheme. This will allow you to launch your application from various sources and with various optional parameters. The URI will have to be formatted as follows:
<Custom Protocol Name>:<The landing page>?[First parameter name]=[First parameter value]&[Second parameter name]=[Second parameter value]
Note that its not mandatory to put the landing page after the semi colon, but it is a good practice. You can use an ID like this:
How to register for an URI association
To register an URI scheme for your app you will have to manually edit the app manifest. In the Solution Explorer open the Properties folder, right click on the WMAppManifest.xml file and select View Code. Scroll down to the end of the Tokens element and add an Extensions element with a Protocol children like this:
<Protocol Name="myappuri" NavUriFragment="encodedLaunchUri=%s" TaskID="_default" />
Just replace myappuri value with the URI you want to use. The other parameters are mandatory and must stay like this.
How to detect that your user launched the app from the URI association
You will have to implement a custom UriMapper that will parse the Uri at the launch of your application and try to detect the source. Following the sample provided above, the UriMapper would look like this in our case:
class AssociationUriMapper : UriMapperBase
private string tempUri;
public override Uri MapUri(Uri uri)
tempUri = System.Net.HttpUtility.UrlDecode(uri.ToString());
// URI association launch for my app detected
// Get the category (after "Category=").
int categoryIndex = tempUri.IndexOf("Category=") + 9;
string category = tempUri.Substring(categoryIndex);
// Redirect to the MainPage.xaml with the proper category to be displayed
return new Uri("/MainPage.xaml?Category=" + category, UriKind.Relative);
// Otherwise perform normal launch.
One more step to ensure that your application will use your new UriMapper, go to App.xamls.cs file in the InitializePhoneApplication() method and add this line:
RootFrame.UriMapper = new AssociationUriMapper();
Your app will now try to detect if it was launched from the normal way or from the URI association, and in this case it will parse the parameters provided and redirect to the proper page.
How to retrive the parameters once you have been redirected
Like for any page navigation in Windows Phone you'll have to check the QueryString in NavigationContext once you've reached your target page to retrieve your parameters
protected override void OnNavigatedTo(NavigationEventArgs e)
Category = int.Parse(NavigationContext.QueryString["Category"]);
What will and will not work
What will trigger your URI association and launch your app:
- Get the URI from NFC tag.
- Get the URI by mail.
- Click on a HTML link containing the URI.
- Webpage redirection with a custom protocol.
- Get the URI from NFC device sharing an URI (e.g. PublishUriMessage(Uri) from ProximityDevice).
What will NOT trigger your URI association and launch your app
- Enter directly the URI in the Web Browser.
- Scan a QR code from Bing search.
What MAY trigger your URI association and launch your app
- Get the URI by SMS. It seems to depend on the uri your registered and could be connected to its lenght
What if many applications registered the same name
In this case the user will be prompted to select which application he want to launch