MP3不會觸發Storyboard.Completed事件

Question

我正在嘗試使用Storyboard的Completed事件來指示音頻文件何時完成播放。 但是，在播放mp3和wav文件時，似乎.Net的行爲會有所不同，並且僅針對WAV觸發事件。

下面是一個XAML和代碼演示該問題：

<Window x:Class="WpfApplication1.MainWindow" 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    Title="MainWindow" Height="350" Width="525" 
    x:Name="mainWind"> 
<Window.Resources> 
    <Storyboard x:Key="mp3StoryBoard" Completed="Storyboard_Completed"> 
     <MediaTimeline Source="001.mp3" Storyboard.TargetName="mediaEl" > 

     </MediaTimeline> 
    </Storyboard> 
    <Storyboard x:Key="wavStoryBoard" Completed="Storyboard_Completed"> 
     <MediaTimeline Source="001.wav" Storyboard.TargetName="mediaEl" > 

     </MediaTimeline> 
    </Storyboard> 
</Window.Resources> 
<Grid> 
    <MediaElement x:Name="mediaEl" Height="120" HorizontalAlignment="Left" Margin="120,94,0,0" VerticalAlignment="Top" Width="160" /> 
    <Button Content="Play MP3" Height="23" HorizontalAlignment="Left" Margin="148,260,0,0" Name="btnMP3" VerticalAlignment="Top" Width="75" Click="button1_Click" /> 
    <Button Content="Play WAV" Height="23" HorizontalAlignment="Left" Margin="267,260,0,0" Name="btnWAV" VerticalAlignment="Top" Width="75" Click="btnWAV_Click" /> 
</Grid> 
</Window> 


using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Text; 
using System.Windows; 
using System.Windows.Controls; 
using System.Windows.Data; 
using System.Windows.Documents; 
using System.Windows.Input; 
using System.Windows.Media; 
using System.Windows.Media.Imaging; 
using System.Windows.Media.Animation; 
using System.Windows.Navigation; 
using System.Windows.Shapes; 

namespace WpfApplication1 
{ 
/// <summary> 
/// Interaction logic for MainWindow.xaml 
/// </summary> 
public partial class MainWindow : Window 
{ 
    public MainWindow() 
    { 
     InitializeComponent(); 
    } 

    private void button1_Click(object sender, RoutedEventArgs e) 
    { 
     Storyboard sb = (Storyboard)this.mainWind.Resources["mp3StoryBoard"]; 
     sb.Begin(); 

    } 

    private void Storyboard_Completed(object sender, EventArgs e) 
    { 
     MessageBox.Show(" Storyboard finished"); 
    } 


    private void btnWAV_Click(object sender, RoutedEventArgs e) 
    { 
     Storyboard sb = (Storyboard)this.mainWind.Resources["wavStoryBoard"]; 
     sb.Begin(); 
    } 
} 

}

會很高興，如果任何人有其中的原因以及如何克服它的想法。

Answer 1

WPF MediaKit包括一個MediaElement替代品，它可能對mp3文件效果更好。

Answer 2

您沒有附加的事件處理程序。

你需要一個

sb.Completed +=Storyboard_Completed; 

之前