我正在从XML解析多个音频文件uri,并将它们绑定到MediaElement的Source属性。我有八个按钮可以触发音频文件。当"自动播放"属性设置为True时,一切都很正常。每个按钮都会触发正确的音频文件。但由于我不希望页面加载后立即开始播放音频,我已将"自动播放"设置为False。现在什么都不管用。页面加载,但按钮不会触发音频文件。如何解决此错误?
代码:
public partial class MainPage : PhoneApplicationPage
{
string name = "C";
public MainPage()
{
InitializeComponent();
}
protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)
{
SetPlayerSource();
base.OnNavigatedTo(e);
}
private void SetPlayerSource()
{
XDocument audioPlayer = XDocument.Load("Audio.xml");
var aani = (from audio in audioPlayer.Descendants("Note")
where audio.Attribute("id").Value == name
select new AudioClass
{
Audio = (string)audio.Element("url").Value
}).SingleOrDefault();
player.Source = new Uri(aani.Audio, UriKind.RelativeOrAbsolute);
}
private void C_Key_Click(object sender, RoutedEventArgs e)
{
var buttonName = (sender as Button).Name;
var underscorePos = buttonName.IndexOf('_');
name = buttonName.Substring(0, underscorePos);
SetPlayerSource();
player.Play();
}
private void D_Key_Click(object sender, RoutedEventArgs e)
{
var buttonName = (sender as Button).Name;
var underscorePos = buttonName.IndexOf('_');
name = buttonName.Substring(0, underscorePos);
SetPlayerSource();
player.Play();
}
XAML:
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="41,-8,-17,8">
<Button x:Name="C_key" Content="" HorizontalAlignment="Left" Height="220" Margin="8,0,0,8" Style="{StaticResource C}" VerticalAlignment="Bottom" Width="75" Click="C_Key_Click"/>
<Button x:Name="D_key" Content="" HorizontalAlignment="Left" Height="220" Margin="87,0,0,8" Style="{StaticResource D}" VerticalAlignment="Bottom" Width="75" Click="D_Key_Click"/>
<Button x:Name="E_key" Content="" HorizontalAlignment="Left" Height="220" Margin="166,0,0,8" Style="{StaticResource E}" VerticalAlignment="Bottom" Width="75" Click="E_Key_Click"/>
<Button x:Name="F_key" Content="" HorizontalAlignment="Left" Height="220" Margin="245,0,0,8" Style="{StaticResource F}" VerticalAlignment="Bottom" Width="75" d:LayoutOverrides="Width" Click="F_Key_Click"/>
<Button x:Name="G_key" Content="" Height="220" Margin="324,0,305,8" Style="{StaticResource G}" VerticalAlignment="Bottom" Click="G_Key_Click"/>
<Button x:Name="A_key" Content="" HorizontalAlignment="Right" Height="220" Margin="0,0,226,8" Style="{StaticResource A}" VerticalAlignment="Bottom" Width="75" Click="A_Key_Click"/>
<Button x:Name="B_key" Content="" HorizontalAlignment="Right" Height="220" Margin="0,0,147,8" Style="{StaticResource B}" VerticalAlignment="Bottom" Width="75" Click="B_Key_Click"/>
<Button x:Name="C2_key" Content="" HorizontalAlignment="Right" Height="220" Margin="0,0,68,8" Style="{StaticResource C2}" VerticalAlignment="Bottom" Width="75" Click="C2_Key_Click"/>
<MediaElement Height="120" HorizontalAlignment="Left" Margin="8,6,0,0" Name="player" VerticalAlignment="Top" Width="160" Source="{Binding Audio}" Volume="1" AutoPlay="False"/>
</Grid>
根据MSDN,在设置Source
属性之前,应先将AutoPlay
设置为false
。
在SetPlayerSource
中设置Source
时,可以从XAML中删除setter。除此之外,代码看起来还不错。
然而,我刚刚意识到,您在呼叫SetPlayerSource
之后直接呼叫Play
。这不会给你的代码在尝试播放之前真正加载媒体的时间。
您需要在MediaOpened
事件上调用Play
。
首先,将MediaElement
中的Name=player
替换为x:Name=player
。这有时会导致其他控制措施出现问题。
如果这不起作用,您可能正在尝试在音频加载完成之前调用Play
方法。相反,请尝试处理MediaOpened
事件并在那里播放该文件。
private void player_MediaOpened(object sender, RoutedEventArgs e)
{
player.Play();
}