Enable relaunching your content from Recall

Recall automatically saves snapshots of your application, however, users won't be able to relaunch back to your content unless you provide a UserActivity at the time of the snapshot. This enables Recall to launch the user back into what was being seen at that time.

A UserActivity refers to something specific the user was working on within your app. For example, when a user is writing a document, a UserActivity could refer to the specific place in the document where the user left off writing. When listening to a music app, the UserActivity could be the playlist that the user last listened to. When drawing on a canvas, the UserActivity could be where the user last made a mark. In summary, a UserActivity represents a destination within your Windows app that a user can return to so that they can resume what they were doing.

Pushing user activities

Whenever the main content in your app changes (like the user opening a different email, opening a different webpage, etc), your app should log a new UserActivitySession so that the system knows what content is currently open. Recall will then associate the most recent UserActivity with the snapshot it saves, and will use the ActivationUri within the activity to allow the user to relaunch back to that content.

We recommend that you push user activities on all PCs, even those not running Recall.

UserActivitySession _previousSession;

private async Task OnContentChangedAsync()
{
    // Dispose of any previous session (which automatically logs the end of the interaction with that content)
    _previousSession?.Dispose();

    // Generate an identifier that uniquely maps to your new content.
    string id = "doc135.txt";

    // Create a new user activity that represents your new content
    var activity = await UserActivityChannel.GetDefault().GetOrCreateUserActivityAsync(id);

    // Populate the required properties
    activity.DisplayText = "doc135.txt";
    activity.ActivationUri = new Uri("my-app://docs/doc135.txt");

    // Save the activity
    await activity.SaveAsync();

    // And start a new session tracking the engagement with this new activity
    _previousSession = activity.CreateSession();
}

Optional: Handling the Requested event

In addition to pushing activities, your app can choose to implement the UserActivityRequested event, which Windows may fire to ensure it has the latest activity from your app.

public void OnLaunched()
{
    UserActivityRequestManager.GetForCurrentView().UserActivityRequested += UserActivityRequested;
}

private async void UserActivityRequested(
    Windows.ApplicationModel.UserActivities.UserActivityRequestManager sender,
    Windows.ApplicationModel.UserActivities.UserActivityRequestedEventArgs args)
{
    // Start a deferral so you can use async code
    var deferral = args.GetDeferral();

    try
    {
        // Generate an identifier that uniquely maps to your current content.
        string id = "doc135.txt";

        // Create a user activity that represents your current content
        var activity = await UserActivityChannel.GetDefault().GetOrCreateUserActivityAsync(id);

        // Populate the required properties
        activity.DisplayText = "doc135.txt";
        activity.ActivationUri = new Uri("my-app://docs/doc135.txt");

        // And return the activity to the event handler
        args.Request.SetUserActivity(activity);
    }

    finally
    {
        // And complete the deferral
        deferral.Complete();
    }
}

Related content

• UserActivity class
• Provide sensitivity labels to Recall with UserActivity ContentInfo - Learn how to supply sensitivity label metadata through UserActivity.ContentInfo for enterprise DLP policy enforcement
• Guidance for developers of web browsers