我正在Rasp Pi 3上制作一个应用程序,我可以在该页面上触发“播放页面”上的按钮以使用页面中的MediaPlayer激活音频播放。一旦我切换到另一个页面,音频将继续在后台播放,但是一旦导航回到“播放页面”,音频仍在播放,但是由于我的mediaPlayer = new MediaPlayer(),我失去了对MediaPlayer的控制。线。如果处于重复模式,我将无法停止播放;如果触发另一则消息,则新消息和现有消息都将同时播放。
即使在页面之间切换,如何确保一次只播放一个MediaPlayer。
请帮忙。谢谢。
编辑代码:
public sealed partial class MessagePage : Page
{
private object syncObj = new object();
public MessagePage()
{
this.InitializeComponent();
startclock();
this.Home.Click += Home_Click;
this.Message.Click += Message_Click;
//mediaPlayer = new MediaPlayer();
mediaPlayer = this.GetInstance();
//mediaPlayer.MediaEnded += MediaPlayer_MediaEnded;
//mediaPlayer.MediaOpened += MediaPlayer_MediaOpened;
}
public MediaPlayer GetInstance()
{
lock (syncObj)
{
if (mediaPlayer == null)
{
mediaPlayer = new MediaPlayer();
mediaPlayer.MediaEnded += MediaPlayer_MediaEnded;
mediaPlayer.MediaOpened += MediaPlayer_MediaOpened;
}
}
return mediaPlayer;
}
}
旧代码:
public MessagePage()
{
this.InitializeComponent();
startclock();
this.Home.Click += Home_Click;
this.Message.Click += Message_Click;
mediaPlayer = new MediaPlayer();
mediaPlayer.MediaEnded += MediaPlayer_MediaEnded;
}
private async void Btn_Click(object sender, RoutedEventArgs e)
{
StorageFolder externalDevices = KnownFolders.RemovableDevices;
IReadOnlyList<StorageFolder> externalDrives = await externalDevices.GetFoldersAsync();
StorageFolder usbStorage = externalDrives[0];
if (usbStorage != null)
{
StorageFolder storageFolder = KnownFolders.RemovableDevices;
StorageFile audioFile = await usbStorage.GetFileAsync("message1.mp3");
mediaPlayer.Source = Windows.Media.Core.MediaSource.CreateFromStorageFile(audioFile);
mediaPlayer.Play();
TextBlock.Text = "Playing Message 1...";
}
else
{
TextBlock.Text = "No USB Storage Detected...";
};
}
最佳答案
您需要在此处使用singleton pattern。单例模式是一种软件设计模式,它将类的实例化限制为一个对象。当仅需要一个对象来协调整个系统中的 Action 时,这很有用。
private static readonly object syncObj = new object();
public MediaPlayer GetInstance()
{
lock (syncObj)
{
if (mediaPlayer == null)
{
mediaPlayer = new MediaPlayer();
mediaPlayer.MediaEnded += MediaPlayer_MediaEnded;
}
}
return mediaPlayer;
}
public MessagePage() { this.InitializeComponent(); startclock(); this.Home.Click += Home_Click; this.Message.Click += Message_Click; //mediaPlayer = new MediaPlayer(); mediaPlayer = this.GetInstance(); }
关于c# - Windows IoT Raspberry Pi 3 C#音频播放在不同的页面,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/46381369/