在 UWP 中完全关闭辅助视图

Question

我正在使用运行我的媒体文件的辅助视图，但是当我使用关闭按钮关闭辅助视图时（媒体仍在播放时）辅助 view/window 关闭但媒体以某种方式继续播放，因为我可以听到声音并且声音来源似乎是主要视图（主应用程序 window）。如何在关闭时完全终止辅助 window？

这是我创建辅助视图的代码。

await CoreApplication.CreateNewView().Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
        {
            var frame = new Frame();
            frame.MinHeight = 200;
            frame.MinWidth = 200;
            compactViewId = ApplicationView.GetForCurrentView().Id;
            frame.Navigate(typeof(CompactNowPlayingPage), caption);
            Window.Current.Content = frame;
            Window.Current.Activate();
            ApplicationView.GetForCurrentView().Title = Title;

        });
        bool viewShown = await ApplicationViewSwitcher.TryShowAsViewModeAsync(compactViewId, ApplicationViewMode.Default);

更新

经过一些调试后，我知道在辅助视图上按下关闭按钮只会隐藏视图，但它会在其线程上保持运行ning，我只希望关闭按钮完全关闭辅助视图，关闭它的线程并销毁整个 window。

更新 2

我按照 windows 对多个视图进行了采样并能够完成所有步骤，代码运行没问题，直到它在发布的事件中达到 Windows.Current.Close()。

然后当它尝试 "Window.Current.Close()" 时它会在发布的事件中给出一个异常。根据文档，由于任何正在进行的更改（可能是因为正在播放媒体文件）会发生异常，但是即使正在播放媒体文件，我也需要强制关闭 window 我该怎么做？这是例外情况：

Message = "COM object that has been separated from its underlying RCW cannot be used."

更新 3

这是最新的更新，我现在不是按照官方示例，只是按照更简单的方法。

打开辅助视图的代码：

await Helpers.DeviceTypeHelper.CompactOpen(e.ClickedItem as Video, identifier); //where identified is just a string for some custom logic in the secondary view.

//following method is located in a helper class within the project
internal static async Task CompactOpen(Video PlayingVideo, string caption)
{
    ApplicationView newView = null;
    await CoreApplication.CreateNewView().Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
    {
        var frame = new Frame();
        frame.Navigate(typeof(CompactNowPlayingPage),new object[] { PlayingVideo,caption});
        Window.Current.Content = frame;
        Window.Current.Activate();
        newView = ApplicationView.GetForCurrentView();
        newView.Title = PlayingVideo.MyVideoFile.DisplayName;
    });

    await ApplicationViewSwitcher.TryShowAsStandaloneAsync(newView.Id);

}

二级视图：

public sealed partial class CompactNowPlayingPage : Page
{
    public CompactNowPlayingViewModel ViewModel { get; } = new CompactNowPlayingViewModel();
    private CustomMediaTransportControls controls;
    public CompactNowPlayingPage()
    {
        InitializeComponent();
        this.Loaded += MediaPage_Loaded;
        this.Unloaded += MediaPage_Unloaded;
        Microsoft.Toolkit.Uwp.UI.Extensions.ApplicationView.SetExtendViewIntoTitleBar(this, true);
        Microsoft.Toolkit.Uwp.UI.Extensions.TitleBar.SetButtonBackgroundColor(this, Colors.Transparent);
    }

    protected override void OnNavigatedTo(NavigationEventArgs e)
    {
        string chk = "";
        var paramm = e.Parameter as object[];
        NowPlayingVideo = paramm[0] as Video;
        var vis = Visibility.Collapsed;
        chk = paramm[1].ToString();
        switch (chk)
        {
            case "library":
                vis = Visibility.Visible;
                break;
            case "playlist":
                vis = Visibility.Visible;
                break;
            case "history":
                vis = Visibility.Collapsed;
                break;
            case "directplay":
                vis = Visibility.Collapsed;
                break;
            default:
                break;
        }
        controls = new CustomMediaTransportControls(NowPlayingVideo,vis);
        Media.TransportControls = controls;
        PlayVideo();
    }
    private Video NowPlayingVideo { get; set; }
    private void PlayVideo()
    {
        if (NowPlayingVideo != null)
        {
            string token = "";
            if (StorageApplicationPermissions.FutureAccessList.Entries.Count == 800)
            {
                var en = StorageApplicationPermissions.FutureAccessList.Entries;
                StorageApplicationPermissions.FutureAccessList.Remove(en.Last().Token);
            }
            token = StorageApplicationPermissions.FutureAccessList.Add(NowPlayingVideo.MyVideoFile);
            Media.Source = null;
            Media.Source = $"winrt://{token}";
            SetViews();
        }
    }

    private void SetViews()
    {
        NowPlayingVideo.Views++;
        Database.DbHelper.UpdateViews(NowPlayingVideo.MyVideoFile.Path);
    }
    private void MediaPage_Loaded(object sender, RoutedEventArgs e)
    {
        Windows.UI.ViewManagement.ApplicationView.GetForCurrentView().Consolidated += MediaPage_Consolidated;
    }

    private void MediaPage_Unloaded(object sender, RoutedEventArgs e)
    {
        Windows.UI.ViewManagement.ApplicationView.GetForCurrentView().Consolidated -= MediaPage_Consolidated;
    }

    private void MediaPage_Consolidated(Windows.UI.ViewManagement.ApplicationView sender, Windows.UI.ViewManagement.ApplicationViewConsolidatedEventArgs args)
    {
        Window.Current.Close();
    }

}

二级视图XAML：

<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
    <vlc:MediaElement AreTransportControlsEnabled="True"
                      Name="Media"                     
                      HardwareAcceleration="True"
                      AutoPlay="True">
    </vlc:MediaElement>
</Grid>

案例 1： 如果我将视频文件放在 Assets 文件夹中并将其作为媒体元素的来源并评论整个运行一切都完美 OnanvigatdTo 辅助页面上的方法。而且我也能够成功关闭 window。 ...

案例 2： 但是当我尝试通过 NowPlayingVideo 对象设置媒体时，如上面的代码所示，我也使用默认传输控制，所以我没有在上面的代码中注释用于分配自定义传输控制的行运行没问题，但是当我尝试关闭 window 时，我在 App.i.g.cs 文件但堆栈跟踪不存在：

Message = "Attempt has been made to use a COM object that does not have a backing class factory." Message = "无法使用与其底层 RCW 分离的 COM 对象。

案例 3： 与案例 2 完全一样，但在这里我取消了自定义传输控制线的注释，所以现在我将自定义传输控制分配给我的媒体元素，这次例外有点不同还有一些堆栈跟踪

StackTrace = " at System.StubHelpers.StubHelpers.GetCOMIPFromRCW_WinRT(Object objSrc, IntPtr pCPCMD, IntPtr& ppTarget)\r\n at Windows.UI.Xaml.DependencyObject.get_Dispatcher()\r\n at VLC.MediaElement.d__160.MoveNext()\r\n---堆栈跟踪结束...

留言="Attempt has been made to use a COM object that does not have a backing class factory."

Answer 1

简短的回答是：您需要确保没有任何内容保留在您的视图实例中，并且您在视图的 Consolidated 事件中调用 Window.Close。更长的代码答案在官方示例中。查看 ViewLifetimeControl.cs 源文件：https://github.com/Microsoft/Windows-universal-samples/tree/master/Samples/MultipleViews/cs

在 UWP 中完全关闭辅助视图

Close secondary view completely in UWP

c#

xaml

multiple-views

application-lifecycle

uwp

更新

更新 2

更新 3