方法 : MediaElement (再生、一時停止、停止、ボリューム、および速度) を制御する
MediaElement を使用して、メディアの再生を制御する方法を次の例に示します。 ここでは、再生、一時停止、停止、メディア内での前後へのスキップ、ボリューム調整、速度比率調整が可能な単純なメディア プレーヤーを作成します。
使用例
次のコードでは、UI を作成します。
.gif "メモ") メモ |
|---|
メディアを対話的に停止、一時停止、および再生できるようにするには、MediaElement の LoadedBehavior プロパティを Manual に設定する必要があります。 |
<Page xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml"
x:Class="SDKSample.MediaElementExample" >
<StackPanel Background="Black">
<!-- To interactively stop, pause, and play the media, the LoadedBehavior
property of the MediaElement must be set to "Manual". -->
<MediaElement Source="media\numbers.wmv" Name="myMediaElement"
Width="450" Height="250" LoadedBehavior="Manual" UnloadedBehavior="Stop" Stretch="Fill"
MediaOpened="Element_MediaOpened" MediaEnded="Element_MediaEnded"/>
<StackPanel HorizontalAlignment="Center" Width="450" Orientation="Horizontal">
<!-- Play button. -->
<Image Source="images\UI_play.gif" MouseDown="OnMouseDownPlayMedia" Margin="5" />
<!-- Pause button. -->
<Image Source="images\UI_pause.gif" MouseDown="OnMouseDownPauseMedia" Margin="5" />
<!-- Stop button. -->
<Image Source="images\UI_stop.gif" MouseDown="OnMouseDownStopMedia" Margin="5" />
<!-- Volume slider. This slider allows a Volume range between 0 and 1. -->
<TextBlock Foreground="White" VerticalAlignment="Center" Margin="5" >Volume</TextBlock>
<Slider Name="volumeSlider" VerticalAlignment="Center" ValueChanged="ChangeMediaVolume"
Minimum="0" Maximum="1" Value="0.5" Width="70"/>
<!-- Volume slider. This slider allows you to change the speed of the media playback. -->
<TextBlock Foreground="White" Margin="5" VerticalAlignment="Center">Speed</TextBlock>
<Slider Name="speedRatioSlider" VerticalAlignment="Center" ValueChanged="ChangeMediaSpeedRatio"
Value="1" Width="70" />
<!-- Seek to slider. Ths slider allows you to jump to different parts of the media playback. -->
<TextBlock Foreground="White" Margin="5" VerticalAlignment="Center">Seek To</TextBlock>
<Slider Name="timelineSlider" Margin="5" ValueChanged="SeekToMediaPosition" Width="70"/>
</StackPanel>
</StackPanel>
</Page>
次のコードでは、サンプル UI コントロールの機能を実装します。 Play、Pause、および Stop メソッドは、それぞれメディアの再生、一時停止、停止に使用します。 MediaElement の Position プロパティを変更すると、メディア内で前後にスキップできます。 最後に、Volume プロパティと SpeedRatio プロパティを使用して、ボリュームとメディアの再生速度を調整します。
Imports System
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Documents
Imports System.Windows.Navigation
Imports System.Windows.Shapes
Imports System.Windows.Data
Imports System.Windows.Media
Imports System.Windows.Input
Namespace SDKSample
Partial Class MediaElementExample
Inherits Page
' Play the media.
Sub OnMouseDownPlayMedia(ByVal sender As Object, ByVal args As MouseButtonEventArgs)
' The Play method will begin the media if it is not currently active or
' resume media if it is paused. This has no effect if the media is
' already running.
myMediaElement.Play()
' Initialize the MediaElement property values.
InitializePropertyValues()
End Sub 'OnMouseDownPlayMedia
' Pause the media.
Sub OnMouseDownPauseMedia(ByVal sender As Object, ByVal args As MouseButtonEventArgs)
' The Pause method pauses the media if it is currently running.
' The Play method can be used to resume.
myMediaElement.Pause()
End Sub 'OnMouseDownPauseMedia
' Stop the media.
Sub OnMouseDownStopMedia(ByVal sender As Object, ByVal args As MouseButtonEventArgs)
' The Stop method stops and resets the media to be played from
' the beginning.
myMediaElement.Stop()
End Sub 'OnMouseDownStopMedia
' Change the volume of the media.
Private Sub ChangeMediaVolume(ByVal sender As Object, ByVal args As RoutedPropertyChangedEventArgs(Of Double))
myMediaElement.Volume = System.Convert.ToDouble(volumeSlider.Value)
End Sub 'ChangeMediaVolume
' Change the speed of the media.
Private Sub ChangeMediaSpeedRatio(ByVal sender As Object, ByVal args As RoutedPropertyChangedEventArgs(Of Double))
myMediaElement.SpeedRatio = System.Convert.ToDouble(speedRatioSlider.Value)
End Sub 'ChangeMediaSpeedRatio
' When the media opens, initialize the "Seek To" slider maximum value
' to the total number of miliseconds in the length of the media clip.
Private Sub Element_MediaOpened(ByVal sender As Object, ByVal args As RoutedEventArgs)
timelineSlider.Maximum = myMediaElement.NaturalDuration.TimeSpan.TotalMilliseconds
End Sub
' When the media playback is finished. Stop() the media to seek to media start.
Private Sub Element_MediaEnded(ByVal sender As Object, ByVal args As RoutedEventArgs)
myMediaElement.Stop()
End Sub
' Jump to different parts of the media (seek to).
Private Sub SeekToMediaPosition(ByVal sender As Object, ByVal args As RoutedPropertyChangedEventArgs(Of Double))
Dim SliderValue As Integer = CType(timelineSlider.Value, Integer)
' Overloaded constructor takes the arguments days, hours, minutes, seconds, miniseconds.
' Create a TimeSpan with miliseconds equal to the slider value.
Dim ts As New TimeSpan(0, 0, 0, 0, SliderValue)
myMediaElement.Position = ts
End Sub
' Set the media's starting Volume and SpeedRatio to the current value of the
' their respective slider controls.
Private Sub InitializePropertyValues()
myMediaElement.Volume = System.Convert.ToDouble(volumeSlider.Value)
myMediaElement.SpeedRatio = System.Convert.ToDouble(speedRatioSlider.Value)
End Sub
End Class 'MediaElementExample
End Namespace 'SDKSample
using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Windows.Data;
using System.Windows.Media;
using System.Windows.Input;
namespace SDKSample
{
public partial class MediaElementExample : Page
{
// Play the media.
void OnMouseDownPlayMedia(object sender, MouseButtonEventArgs args)
{
// The Play method will begin the media if it is not currently active or
// resume media if it is paused. This has no effect if the media is
// already running.
myMediaElement.Play();
// Initialize the MediaElement property values.
InitializePropertyValues();
}
// Pause the media.
void OnMouseDownPauseMedia(object sender, MouseButtonEventArgs args)
{
// The Pause method pauses the media if it is currently running.
// The Play method can be used to resume.
myMediaElement.Pause();
}
// Stop the media.
void OnMouseDownStopMedia(object sender, MouseButtonEventArgs args)
{
// The Stop method stops and resets the media to be played from
// the beginning.
myMediaElement.Stop();
}
// Change the volume of the media.
private void ChangeMediaVolume(object sender, RoutedPropertyChangedEventArgs<double> args)
{
myMediaElement.Volume = (double)volumeSlider.Value;
}
// Change the speed of the media.
private void ChangeMediaSpeedRatio(object sender, RoutedPropertyChangedEventArgs<double> args)
{
myMediaElement.SpeedRatio = (double)speedRatioSlider.Value;
}
// When the media opens, initialize the "Seek To" slider maximum value
// to the total number of miliseconds in the length of the media clip.
private void Element_MediaOpened(object sender, EventArgs e)
{
timelineSlider.Maximum = myMediaElement.NaturalDuration.TimeSpan.TotalMilliseconds;
}
// When the media playback is finished. Stop() the media to seek to media start.
private void Element_MediaEnded(object sender, EventArgs e)
{
myMediaElement.Stop();
}
// Jump to different parts of the media (seek to).
private void SeekToMediaPosition(object sender, RoutedPropertyChangedEventArgs<double> args)
{
int SliderValue = (int)timelineSlider.Value;
// Overloaded constructor takes the arguments days, hours, minutes, seconds, miniseconds.
// Create a TimeSpan with miliseconds equal to the slider value.
TimeSpan ts = new TimeSpan(0, 0, 0, 0, SliderValue);
myMediaElement.Position = ts;
}
void InitializePropertyValues()
{
// Set the media's starting Volume and SpeedRatio to the current value of the
// their respective slider controls.
myMediaElement.Volume = (double)volumeSlider.Value;
myMediaElement.SpeedRatio = (double)speedRatioSlider.Value;
}
}
}