(UWP) How to activate the “Taskbar Miniplayer” like in Groove

问题

I use the BackgroundMediaPlayer for my App to play Audio in the Background. Now i see these buttons:

How can i activate them?

回答1:

In order to make the media controls from the taskbar to work, you need to load and configure the SystemMediaTransportControls from the foreground application AND the background task. If you are doing it only from the background task, the controls will be displayed but they will remain disabled.

In your foreground application, you should have the following code:

var smtc = SystemMediaTransportControls.GetForCurrentView();
smtc.ButtonPressed += smtc_ButtonPressed;
smtc.PropertyChanged += smtc_PropertyChanged;
smtc.IsEnabled = true;
smtc.IsPauseEnabled = true;
smtc.IsPlayEnabled = true;
smtc.IsNextEnabled = true;
smtc.IsPreviousEnabled = true;

And in the background task, you should have :

smtc = BackgroundMediaPlayer.Current.SystemMediaTransportControls;
smtc.ButtonPressed += smtc_ButtonPressed;
smtc.PropertyChanged += smtc_PropertyChanged;
smtc.IsEnabled = true;
smtc.IsPauseEnabled = true;
smtc.IsPlayEnabled = true;
smtc.IsNextEnabled = true;
smtc.IsPreviousEnabled = true;

Beware that the API to get the control instance is not the same:
SystemMediaTransportControls.GetForCurrentView() in the foreground app and BackgroundMediaPlayer.Current.SystemMediaTransportControls in the background task.

You will have to support the button pressed event in the two (foreground + background)

回答2:

That's System Media Transport Controls and you should add code to handle click event.
Here is official sample:

public MainPage()
{
this.InitializeComponent();

// Hook up app to system transport controls.
systemMediaControls = SystemMediaTransportControls.GetForCurrentView();
systemMediaControls.ButtonPressed += SystemControls_ButtonPressed;

// Register to handle the following system transpot control buttons.
systemMediaControls.IsPlayEnabled = true;
systemMediaControls.IsPauseEnabled = true;
}

async void SystemControls_ButtonPressed(SystemMediaTransportControls sender,
SystemMediaTransportControlsButtonPressedEventArgs args)
{
switch (args.Button)
  {
    case SystemMediaTransportControlsButton.Play:
        await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () =>
        {
            mediaElement.Play();
        });
        break;
    case SystemMediaTransportControlsButton.Pause:
        await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () =>
        {
            mediaElement.Pause();
        });
        break;
    default:
        break;
  }
}

来源：https://stackoverflow.com/questions/37786261/uwp-how-to-activate-the-taskbar-miniplayer-like-in-groove