/// <summary>
/// 执行暂停命令
/// </summary>
public void Pause()
{
if (IsBackgroundRunning)
{
BackgroundAudioSettingsHelper.SetValue(BackgroundAudioSettingsConstants.TRACK_INDEX, CurrentPlayingIndex);
BackgroundAudioSettingsHelper.SetValue(BackgroundAudioSettingsConstants.POSITION, CurrentPlayer.Position.ToString());
CurrentPlayer.Pause();
}
}
/// <summary>
/// 后台任务的入口方法
/// </summary>
/// <param name="taskInstance">表示当前任务的实例</param>
public void Run(IBackgroundTaskInstance taskInstance)
{
//初始化后台消息处理的线程锁
o = new object();
//初始化系统音频控制器
smtc = BackgroundMediaPlayer.Current.SystemMediaTransportControls;
smtc.ButtonPressed += Smtc_ButtonPressed;
smtc.PropertyChanged += Smtc_PropertyChanged;
smtc.IsEnabled = true;
smtc.IsNextEnabled = true;
smtc.IsPreviousEnabled = true;
smtc.IsPlayEnabled = true;
smtc.IsPauseEnabled = true;
//获取前台APP状态
var appState = BackgroundAudioSettingsHelper.GetValue(BackgroundAudioSettingsConstants.APP_STATE);
if (appState == null)
{
foregroundAppState = AppState.Unknown;
}
else
{
foregroundAppState = EnumHelper.Parse <AppState>(appState.ToString());
}
//注册后台播放器的状态改变事件
BackgroundMediaPlayer.Current.CurrentStateChanged += Current_CurrentStateChanged;
//注册后台播放器发生错误时的事件
BackgroundMediaPlayer.Current.MediaFailed += Current_MediaFailed;
BackgroundMediaPlayer.Current.MediaEnded += Current_MediaEnded;
//注册后台播放器接收前台消息事件
BackgroundMediaPlayer.MessageReceivedFromForeground += BackgroundMediaPlayer_MessageReceivedFromForeground;
//如果前台APP未处于挂起状态，发送后台音频启动消息给前台
if (foregroundAppState != AppState.Suspended)
{
MessageService.SendMessageToForeground(new BackgroundAudioTaskStartedMessage());
}
//保存后台音频任务的启动状态
BackgroundAudioSettingsHelper.SetValue(BackgroundAudioSettingsConstants.BACKGROUND_TASK_STATE, BackgroundTaskState.Running.ToString());
deferral = taskInstance.GetDeferral();
backgroundTaskStarted.Set();
//注册后台任务结束事件
taskInstance.Task.Completed += Task_Completed;
//注册后台任务取消事件
taskInstance.Canceled += TaskInstance_Canceled;
}
/// <summary>
/// Invoked when the application is launched normally by the end user. Other entry points
/// will be used such as when the application is launched to open a specific file.
/// </summary>
/// <param name="e">Details about the launch request and process.</param>
protected override void OnLaunched(LaunchActivatedEventArgs e)
{
//#if DEBUG
// if (System.Diagnostics.Debugger.IsAttached)
// {
// this.DebugSettings.EnableFrameRateCounter = true;
// }
//#endif
//Frame rootFrame = Window.Current.Content as Frame;
MainFrame = Window.Current.Content as Frame;
// Do not repeat app initialization when the Window already has content,
// just ensure that the window is active
if (MainFrame == null)
{
// Create a Frame to act as the navigation context and navigate to the first page
MainFrame = new Frame();
MainFrame.NavigationFailed += OnNavigationFailed;
if (e.PreviousExecutionState == ApplicationExecutionState.Terminated)
{
//TODO: Load state from previously suspended application
}
// Place the frame in the current Window
Window.Current.Content = MainFrame;
}
if (e.PrelaunchActivated == false)
{
if (MainFrame.Content == null)
{
// When the navigation stack isn't restored navigate to the first page,
// configuring the new page by passing required information as a navigation
// parameter
MainFrame.Navigate(typeof(MainPage), e.Arguments);
}
// Ensure the current window is active
Window.Current.Activate();
BackgroundAudioSettingsHelper.SetValue(BackgroundAudioSettingsConstants.APP_STATE, AppState.Active.ToString());
try
{
UDPServer.StartService("14288");
RemoteControlService.StartService();
}
catch (Exception ex)
{
throw new Exception("启动UDP服务失败", ex);
}
}
DispatcherHelper.Initialize();
}
/// <summary>
/// 后台任务取消的event handler
/// </summary>
/// <param name="sender"></param>
/// <param name="reason">取消原因</param>
private void TaskInstance_Canceled(IBackgroundTaskInstance sender, BackgroundTaskCancellationReason reason)
{
Debug.WriteLine("BackgroundAudioTask " + sender.Task.TaskId + " Cancel Requested...");
try
{
backgroundTaskStarted.Reset();
//保存前后台任务状态和歌曲播放信息
BackgroundAudioSettingsHelper.SetValue(BackgroundAudioSettingsConstants.TRACK_INDEX, playbackList.CurrentItemIndex);
BackgroundAudioSettingsHelper.SetValue(BackgroundAudioSettingsConstants.POSITION, BackgroundMediaPlayer.Current.Position.ToString());
BackgroundAudioSettingsHelper.SetValue(BackgroundAudioSettingsConstants.BACKGROUND_TASK_STATE, BackgroundTaskState.Canceled.ToString());
BackgroundAudioSettingsHelper.SetValue(BackgroundAudioSettingsConstants.APP_STATE, Enum.GetName(typeof(AppState), foregroundAppState));
//清空播放列表
if (playbackList != null)
{
//playbackList.CurrentItemChanged -= PlaybackList_CurrentItemChanged;
playbackList = null;
}
//取消注册时间
BackgroundMediaPlayer.MessageReceivedFromForeground -= BackgroundMediaPlayer_MessageReceivedFromForeground;
smtc.ButtonPressed -= Smtc_ButtonPressed;
smtc.PropertyChanged -= Smtc_PropertyChanged;
//发送后台任务停止消息给前台
MessageService.SendMessageToForeground(new BackgroundAudioTaskStopedMessage());
//关闭后台播放器
BackgroundMediaPlayer.Shutdown();
}
catch (Exception ex)
{
Debug.WriteLine(ex.ToString() + " " + ex.Message);
}
finally
{
deferral.Complete();
Debug.WriteLine("BackgroundAudioTask Cancel Completed");
}
}
/// <summary>
/// 后台任务异常关闭时，重新启动关闭的后台任务
/// </summary>
private void ResetAfterLostBackground()
{
BackgroundMediaPlayer.Shutdown();
_isBackgroundRunning = false;
BackgroundAudioTaskStarted.Reset();
BackgroundAudioSettingsHelper.SetValue(BackgroundAudioSettingsConstants.BACKGROUND_TASK_STATE, BackgroundTaskState.Unknown.ToString());
try
{
BackgroundMediaPlayer.MessageReceivedFromBackground += BackgroundMediaPlayer_MessageReceivedFromBackground;
}
catch (Exception ex)
{
if (ex.HResult == RPC_S_SERVER_UNAVAILABLE)
{
throw new Exception("Fail to get a media instance", ex);
}
throw ex;
}
}
/// <summary>
/// 接收到前台消息的event handler
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void BackgroundMediaPlayer_MessageReceivedFromForeground(object sender, MediaPlayerDataReceivedEventArgs e)
{
lock (o)
{
Debug.WriteLine("接收消息" + e.Data);
AppSuspendingMessage appSuspendingMessage;
if (MessageService.TryParseMessage(e.Data, out appSuspendingMessage))
{
Debug.WriteLine("App Suspending");
foregroundAppState = AppState.Suspended;
BackgroundAudioSettingsHelper.SetValue(BackgroundAudioSettingsConstants.TRACK_INDEX, playbackList == null ? uint.MinValue : playbackList.CurrentItemIndex);
return;
}
AppResumedMessage appResumedMessage;
if (MessageService.TryParseMessage(e.Data, out appResumedMessage))
{
Debug.WriteLine("App Resumed");
foregroundAppState = AppState.Active;
return;
}
StartPlaybackMessage startPlaybackMessage;
if (MessageService.TryParseMessage(e.Data, out startPlaybackMessage))
{
Debug.WriteLine("Starting Playback");
StartPlayback();
return;
}
SkipNextMessage skipNextMessage;
if (MessageService.TryParseMessage(e.Data, out skipNextMessage))
{
Debug.WriteLine("Skip to Next");
SkipToNext();
return;
}
SkipPreviousMessage skipPreviousMessage;
if (MessageService.TryParseMessage(e.Data, out skipPreviousMessage))
{
Debug.WriteLine("Skip to Previous");
SkipToPrevious();
return;
}
UpdatePlaybackListMessage updatePlaybackListMessage;
if (MessageService.TryParseMessage(e.Data, out updatePlaybackListMessage))
{
Debug.WriteLine("Update Playback list");
//CreatePlaybackList(updatePlaybackListMessage.Songs);
CreatePlaylist(updatePlaybackListMessage.Songs);
isFirstTimeToStart = !updatePlaybackListMessage.IsResumed;
return;
}
TrackChangeMessage trackChangeMessage;
if (MessageService.TryParseMessage(e.Data, out trackChangeMessage))
{
Debug.WriteLine("---------------Track Change" + trackChangeMessage.TrackIndex + "当前track:" + currentIndex);
int index = trackChangeMessage.TrackIndex;
//smtc.PlaybackStatus = MediaPlaybackStatus.Changing;
try
{
//currentIndex = (int)index;
//var item = playbackList.MoveTo(index);
PlayIndex(index);
}
catch { }
//int index = playbackList.Items.ToList().FindIndex(p => (string)p.Source.CustomProperties["filename"] == trackChangeMessage.TrackFile);
//Debug.WriteLine("切换歌曲： " + index + "---" + trackChangeMessage.TrackFile);
//smtc.PlaybackStatus = MediaPlaybackStatus.Changing;
//playbackList.MoveTo((uint)index);
return;
}
Debug.WriteLine("处理消息结束");
}
}