PlayToSource.Next 属性

定义

命名空间:

Windows.Media.PlayTo

获取或设置下一个“播放到”源元素。

public:
 property PlayToSource ^ Next { PlayToSource ^ get(); void set(PlayToSource ^ value); };

/// [get: Windows.Foundation.Metadata.Deprecated("PlayToSource may be altered or unavailable for releases after Windows 10. Instead, use CastingSource.", Windows.Foundation.Metadata.DeprecationType.Deprecate, 65536, "Windows.Foundation.UniversalApiContract")]
/// [set: Windows.Foundation.Metadata.Deprecated("PlayToSource may be altered or unavailable for releases after Windows 10. Instead, use CastingSource.", Windows.Foundation.Metadata.DeprecationType.Deprecate, 65536, "Windows.Foundation.UniversalApiContract")]
PlayToSource Next();

void Next(PlayToSource value);

public PlayToSource Next { [Windows.Foundation.Metadata.Deprecated("PlayToSource may be altered or unavailable for releases after Windows 10. Instead, use CastingSource.", Windows.Foundation.Metadata.DeprecationType.Deprecate, 65536, "Windows.Foundation.UniversalApiContract")] get; [Windows.Foundation.Metadata.Deprecated("PlayToSource may be altered or unavailable for releases after Windows 10. Instead, use CastingSource.", Windows.Foundation.Metadata.DeprecationType.Deprecate, 65536, "Windows.Foundation.UniversalApiContract")] set; }

var playToSource = playToSource.next;
playToSource.next = playToSource;

Public Property Next As PlayToSource

属性值

PlayToSource

下一个“播放到”源元素。

属性

DeprecatedAttribute

示例

// Set up the Play To contract.

// Used to pass an image to Play To that will not be removed/destroyed
// by the slide show logic. For example, if the user opens the Devices
// charm and the sourcerequested event fires, but the image display timeout
// completes before the user selects a target device, then the image that
// was being displayed is removed and destroyed. initialImage is never 
// destroyed so Play To will always have a valid source to stream.
Image initialImage = null;

private async void SourceRequested(Windows.Media.PlayTo.PlayToManager sender, 
                             Windows.Media.PlayTo.PlayToSourceRequestedEventArgs e)
{
    var deferral = e.SourceRequest.GetDeferral();

    await dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
    () =>
    {
        initialImage = new Image();

        // Use the statechanged event of the image passed to Play To to determine when
        // the image is finally connected to the Play To Receiver.
        initialImage.PlayToSource.Connection.StateChanged += InitialImageConnectionStateChanged;

        // Provide Play To with the first image to stream.
        e.SourceRequest.SetSource(initialImage.PlayToSource);

        deferral.Complete();
    });
}

private async void InitialImageConnectionStateChanged(Windows.Media.PlayTo.PlayToConnection sender,
                                                      Windows.Media.PlayTo.PlayToConnectionStateChangedEventArgs e)
{
        if (e.CurrentState == Windows.Media.PlayTo.PlayToConnectionState.Connected) {

            await dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, 
                async () =>
                {
                    // Clear any existing timeout.
                    if (timer != null) { timer.Stop(); }

                    // Clear the slide show panel.
                    SlideShowPanel.Children.Clear();

                    // Set the slide show objects and values to show that we are streaming.
                    streaming = true;
                    DisconnectButton.Visibility = Visibility.Visible;
                    InstructionsBlock.Visibility = Visibility.Collapsed;

                    // Queue and display the next image.
                    var image = await QueueImage(currentImage, true);
                    initialImage.PlayToSource.Next = image.PlayToSource;
                    initialImage.PlayToSource.PlayNext();
                });
        };
}

// Update the once the user has selected a device to stream to.

private async void SourceSelected(Windows.Media.PlayTo.PlayToManager sender, 
                            Windows.Media.PlayTo.PlayToSourceSelectedEventArgs e)
{
    await dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        () =>
        {
            DisconnectButton.Click += DisconnectButtonClick;
            MessageBlock.Text = "Streaming to " + e.FriendlyName + "...";
            DeviceBlock.Text = e.FriendlyName + ".\nClick here to disconnect.";
            var imageBitmap = new Windows.UI.Xaml.Media.Imaging.BitmapImage();
            imageBitmap.SetSource(e.Icon);
            IconImage.Source = imageBitmap;
        });
}

private void DisconnectButtonClick(object sender, RoutedEventArgs e)
{
    Windows.Media.PlayTo.PlayToManager.ShowPlayToUI();
}

' Set up the Play To contract.

' Used to pass an image to Play To that will not be removed/destroyed
' by the slide show logic. For example, if the user opens the Devices
' charm and the sourcerequested event fires, but the image display timeout
' completes before the user selects a target device, then the image that
' was being displayed is removed and destroyed. initialImage is never 
' destroyed so Play To will always have a valid source to stream.
Private initialImage As Image = Nothing

Private Async Sub SourceRequested(sender As Windows.Media.PlayTo.PlayToManager,
                             e As Windows.Media.PlayTo.PlayToSourceRequestedEventArgs)

    Dim deferral = e.SourceRequest.GetDeferral()

    Await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
    Sub()
        initialImage = New Image()

        ' Use the statechanged event of the image passed to Play To to determine when
        ' the image is finally connected to the Play To Receiver.
        AddHandler initialImage.PlayToSource.Connection.StateChanged, AddressOf InitialImageConnectionStateChanged

        ' Provide Play To with the first image to stream.
        e.SourceRequest.SetSource(initialImage.PlayToSource)

        deferral.Complete()
    End Sub)
End Sub

Private Async Sub InitialImageConnectionStateChanged(sender As Windows.Media.PlayTo.PlayToConnection,
                                                         e As Windows.Media.PlayTo.PlayToConnectionStateChangedEventArgs)

    If e.CurrentState = Windows.Media.PlayTo.PlayToConnectionState.Connected Then

        Await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
            Async Sub()
                ' Clear any existing timeout.
                If timer IsNot Nothing Then timer.Stop()

                ' Clear the slide show panel.
                SlideShowPanel.Children.Clear()

                ' Set the slide show objects and values to show that we are streaming.
                streaming = True
                DisconnectButton.Visibility = Visibility.Visible
                InstructionsBlock.Visibility = Visibility.Collapsed

                ' Queue and display the next image.
                Dim image = Await QueueImage(currentImage, True)
                initialImage.PlayToSource.Next = image.PlayToSource
                initialImage.PlayToSource.PlayNext()
            End Sub)
    End If
End Sub

' Update the once the user has selected a device to stream to.

Private Async Sub SourceSelected(sender As Windows.Media.PlayTo.PlayToManager,
                                 e As Windows.Media.PlayTo.PlayToSourceSelectedEventArgs)

    Await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        Sub()
            AddHandler DisconnectButton.Click, AddressOf DisconnectButtonClick
            MessageBlock.Text = "Streaming to " & e.FriendlyName & "..."
            DeviceBlock.Text = e.FriendlyName & "." & vbCr & "Click here to disconnect."
            Dim imageBitmap = New Windows.UI.Xaml.Media.Imaging.BitmapImage()
            imageBitmap.SetSource(e.Icon)
            IconImage.Source = imageBitmap
        End Sub)
End Sub

Private Sub DisconnectButtonClick()
    Windows.Media.PlayTo.PlayToManager.ShowPlayToUI()
End Sub

注解

有关使用 Next 属性的示例，请参阅 媒体强制转换。

另请参阅

• 播放到示例
• PlayToReceiver 示例
• 媒体服务器示例