Question

我正在开发与UWP兼容的Xamarin.Forms应用程序。我的要求是播放，暂停，前进，后退录制的音频文件。为此，我在Xamarin.Forms可移植项目中创建了一个接口

    public interface IRecordAudio 
    {        
         Task<TimeSpan> SetSource(Stream _stream);
         void PlayAudio();
         void ForwardAudio();
         void RewindAudio();
         void PauseAudio();
    }

以及UWP项目中接口的实现如下：

   public class RecordAudioUWP : IRecordAudio
   { 
        public async Task<TimeSpan> SetSource(Stream _stream)
        {
             StorageFolder local = Windows.Storage.ApplicationData.Current.LocalFolder;
             var folder = await local.GetFolderAsync("Recordings");
             var file = await folder.GetFileAsync("MySound.MP3");
             var stream = await file.OpenAsync(Windows.Storage.FileAccessMode.Read);
             element.SetSource(stream, "");
             MusicProperties properties = await 
             file.Properties.GetMusicPropertiesAsync();
             TimeSpan myTrackDuration = properties.Duration;
             return myTrackDuration;
         }

         public void PlayAudio()
         {
             element.Play();
         }

         public void ForwardAudio()  //Not Working
         {
             element.Position += TimeSpan.FromSeconds(10);
         }

         public void PauseAudio()
         {
             element.Pause();
         }

         public void RewindAudio()  //Not Working
         {
             element.Position -= TimeSpan.FromMinutes(1);
         } 
   }

正确设置了音频源。音频正确播放和暂停。我在前进和后退音频文件时遇到问题。

请让我知道我做错了什么。感谢

Answer 1

在Windows 10中，构建1607，我们建议您使用MediaPlayerElement代替MediaElement。 MediaPlayerElement具有与MediaElement相同的功能，同时还支持更高级的媒体播放方案。此外，媒体播放的所有未来改进都将在MediaPlayerElement中进行。

您可以使用MediaPlayerElement代替MediaElement，如下所示：

public class RecordAudioUWP : IRecordAudio
{
    private MediaPlayerElement element;      
    private MediaPlayer player;
    public async Task<TimeSpan> SetSource(Stream _stream)
    {
        element = new MediaPlayerElement();

        StorageFolder local = Windows.Storage.ApplicationData.Current.LocalFolder;
        var folder = await local.GetFolderAsync("Recordings");
        var file = await folder.GetFileAsync("MySound.MP3");
        var stream = await file.OpenAsync(Windows.Storage.FileAccessMode.Read);
        element.Source = MediaSource.CreateFromStream(stream,"");

        player = element.MediaPlayer;
        MusicProperties properties = await
        file.Properties.GetMusicPropertiesAsync();
        TimeSpan myTrackDuration = properties.Duration;
        return myTrackDuration;
    }

    public void PlayAudio()
    {
        player.Play();
    }

    public void ForwardAudio()  
    {
        var session = player.PlaybackSession;
        session.Position += TimeSpan.FromSeconds(10);  

    }

    public void PauseAudio()
    {
        player.Pause();
    }

    public void RewindAudio() 
    {
        var session = player.PlaybackSession;
        session.Position -= TimeSpan.FromMinutes(1);
    }
}

媒体元素UWP中的前向和后向音频

1 个答案: