Windows Phone: Navigate between apps - windows-phone-7

Question

I have an app that needs to include a links to a second app in the same phone.
If the app is not installed the link should point to the windows store to install it (that part is working fine).
But if the app is already installed the link should go straight to the app and open it. How can I do that?
The app has two versions one form WP7 and other from WP8. if the solution is different for them please point the difference.
Thanks for the help...

Answer 1

I believe a URI Association is what you want. You should be able to create a different association in your WP7 app and in your WP8 app, and handle them accordingly.
A URI association allows your app to automatically launch when another app launches a special URI.
Also note:
If you are interested only in launching your own apps, consider using
APIs from the Windows.Phone.Management.Deployment namespace. You can
use this API to check for other apps that you’ve published, and then
launch them if they’re installed.
You basically just need to update the WMAppManifest.xml file to include the URI Association and then listen for that URI. Example:
<Extensions>
<Protocol Name="contoso" NavUriFragment="encodedLaunchUri=%s" TaskID="_default" />
</Extensions>
Then you can use a custom URI Mapper to handle your association (full example in top link above):
public override Uri MapUri(Uri uri)
{
tempUri = System.Net.HttpUtility.UrlDecode(uri.ToString());
// URI association launch for contoso.
if (tempUri.Contains("contoso:ShowProducts?CategoryID="))
{
// Get the category ID (after "CategoryID=").
int categoryIdIndex = tempUri.IndexOf("CategoryID=") + 11;
string categoryId = tempUri.Substring(categoryIdIndex);
// Map the show products request to ShowProducts.xaml
return new Uri("/ShowProducts.xaml?CategoryID=" + categoryId, UriKind.Relative);
}
// Otherwise perform normal launch.
return uri;
}
Hope this helps!

Answer 2

Is the secondary app one that you have created? If so, do something like this:
IEnumerable<Package> packages = InstallationManager.FindPackagesForCurrentPublisher();
foreach (Package package in packages)
{
if (package.Id.ProductId.ToString().ToLower() == "product id of secondary app")
{
//Launch the app
package.Launch();
}
}
Make sure that your publisher ids match in the WMAppManifest for both apps.
If this secondary app was published by someone else, you'll need to use a custom Uri schema. The app needs to have this feature added by the developer, you can't just launch any app.