Toast progress bar and data binding

Using a progress bar inside your toast notification allows you to convey the status of long-running operations to the user, like downloads, video rendering, exercise goals, and more.

A progress bar inside a toast can either be "indeterminate" (no specific value, animated dots indicate an operation is occurring) or "determinate" (a specific percent of the bar is filled, like 60%).

Important APIs: NotificationData class, ToastNotifier.Update method, ToastNotification class

The picture below shows a determinate progress bar with all of its corresponding properties labeled.

Here's how you would generate the notification seen above...

new ToastContentBuilder()
    .AddText("Downloading your weekly playlist...")
    .AddVisualChild(new AdaptiveProgressBar()
    {
        Title = "Weekly playlist",
        Value = 0.6,
        ValueStringOverride = "15/26 songs",
        Status = "Downloading..."
    });

<toast>
    <visual>
        <binding template="ToastGeneric">
            <text>Downloading your weekly playlist...</text>
            <progress
                title="Weekly playlist"
                value="0.6"
                valueStringOverride="15/26 songs"
                status="Downloading..."/>
        </binding>
    </visual>
</toast>

However, you'll need to dynamically update the values of the progress bar for it to actually be "live". This can be done by using data binding to update the toast.

Using data binding to update a toast

Using data binding involves the following steps...

1. Construct toast content that utilizes data bound fields
2. Assign a Tag (and optionally a Group) to your ToastNotification
3. Define your initial Data values on your ToastNotification
4. Send the toast
5. Utilize Tag and Group to update the Data values with new values

The following code snippet shows steps 1-4. The next snippet will show how to update the toast Data values.

using Windows.UI.Notifications;
using Microsoft.Toolkit.Uwp.Notifications;
 
public void SendUpdatableToastWithProgress()
{
    // Define a tag (and optionally a group) to uniquely identify the notification, in order update the notification data later;
    string tag = "weekly-playlist";
    string group = "downloads";
 
    // Construct the toast content with data bound fields
    var content = new ToastContentBuilder()
        .AddText("Downloading your weekly playlist...")
        .AddVisualChild(new AdaptiveProgressBar()
        {
            Title = "Weekly playlist",
            Value = new BindableProgressBarValue("progressValue"),
            ValueStringOverride = new BindableString("progressValueString"),
            Status = new BindableString("progressStatus")
        })
        .GetToastContent();
 
    // Generate the toast notification
    var toast = new ToastNotification(content.GetXml());
 
    // Assign the tag and group
    toast.Tag = tag;
    toast.Group = group;
 
    // Assign initial NotificationData values
    // Values must be of type string
    toast.Data = new NotificationData();
    toast.Data.Values["progressValue"] = "0.6";
    toast.Data.Values["progressValueString"] = "15/26 songs";
    toast.Data.Values["progressStatus"] = "Downloading...";
 
    // Provide sequence number to prevent out-of-order updates, or assign 0 to indicate "always update"
    toast.Data.SequenceNumber = 1;
 
    // Show the toast notification to the user
    ToastNotificationManager.CreateToastNotifier().Show(toast);
}

Then, when you want to change your Data values, use the Update method to provide the new data without re-constructing the entire toast payload.

using Windows.UI.Notifications;
 
public void UpdateProgress()
{
    // Construct a NotificationData object;
    string tag = "weekly-playlist";
    string group = "downloads";
 
    // Create NotificationData and make sure the sequence number is incremented
    // since last update, or assign 0 for updating regardless of order
    var data = new NotificationData
    {
        SequenceNumber = 2
    };

    // Assign new values
    // Note that you only need to assign values that changed. In this example
    // we don't assign progressStatus since we don't need to change it
    data.Values["progressValue"] = "0.7";
    data.Values["progressValueString"] = "18/26 songs";

    // Update the existing notification's data by using tag/group
    ToastNotificationManager.CreateToastNotifier().Update(data, tag, group);
}

Using the Update method rather than replacing the entire toast also ensures that the toast notification stays in the same position in Action Center and doesn't move up or down. It would be quite confusing to the user if the toast kept jumping to the top of Action Center every few seconds while the progress bar filled!

The Update method returns an enum, NotificationUpdateResult, which lets you know whether the update succeeded or whether the notification couldn't be found (which means the user has likely dismissed your notification and you should stop sending updates to it). We do not recommend popping another toast until your progress operation has been completed (like when the download completes).

Elements that support data binding

The following elements in toast notifications support data binding

• All properties on AdaptiveProgress
• The Text property on the top-level AdaptiveText elements

Update or replace a notification

Since Windows 10, you could always replace a notification by sending a new toast with the same Tag and Group. So what's the difference between replacing the toast and updating the toast's data?

In general, updating is useful for...

• Information that frequently changes in a short period of time and doesn't require being brought to the front of the user's attention
• Subtle changes to your toast content, like changing 50% to 65%

Often times, after your sequence of updates have completed (like the file has been downloaded), we recommend replacing for the final step, because...

• Your final notification likely has drastic layout changes, like removal of the progress bar, addition of new buttons, etc
• The user might have dismissed your pending progress notification since they don't care about watching it download, but still want to be notified with a popup toast when the operation is completed

Related topics

• Full code sample on GitHub
• Toast content documentation