WPF 實作音訊檔案循環順序播放完整方案

WPF 音訊播放類別比較

結論：**MediaElement 最適合 WPF 應用**，功能最完整且可直接寫在 XAML。

架構設計：繼承 MediaElement 封裝播放清單邏輯

public class MediaManager : MediaElement {
    private readonly ObservableCollection<string> _files = new();
    private int _index = 0;
    private readonly string[] _filters = { "*.mp3", "*.wav", "*.wma" };

    public MediaManager() {
        LoadedBehavior = MediaState.Manual;
        UnloadedBehavior = MediaState.Manual;
        MediaEnded += OnMediaEnded;
        LoadFilesFromConfig();
    }

    private void LoadFilesFromConfig() {
        string root = ConfigurationManager.AppSettings["MediaRoot"];
        if (Directory.Exists(root)) ScanDirectory(new DirectoryInfo(root));
    }

    private void ScanDirectory(DirectoryInfo dir) {
        foreach (var filter in _filters) {
            foreach (var file in dir.GetFiles(filter)) _files.Add(file.FullName);
        }
        foreach (var sub in dir.GetDirectories()) ScanDirectory(sub);
    }

    public void PlayList() {
        if (_files.Count == 0) return;
        Source = new Uri(_files[_index], UriKind.Absolute);
        Play();
    }

    private void OnMediaEnded(object sender, RoutedEventArgs e) {
        _index = (_index + 1) % _files.Count; // 循環
        Source = new Uri(_files[_index], UriKind.Absolute);
        Play();
    }
}

XAML 使用

<Window x:Class="MediaApp.MainWindow"
        xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:MediaApp"
        Title="音樂播放器" Height="200" Width="400" Loaded="Window_Loaded">
    <StackPanel>
        <local:MediaManager x:Name="Player" />
        <TextBlock Text="{Binding Source, ElementName=Player, StringFormat='正在播放: {0}'}" />
        <Slider Maximum="{Binding NaturalDuration.TimeSpan.TotalSeconds, ElementName=Player}"
                Value="{Binding Position.TotalSeconds, ElementName=Player, Mode=TwoWay}" />
    </StackPanel>
</Window>

Code-Behind

public partial class MainWindow : Window {
    public MainWindow() => InitializeComponent();
    private void Window_Loaded(object sender, RoutedEventArgs e) => Player.PlayList();
}

App.config 設定媒體庫根目錄

<appSettings>
  <add key="MediaRoot" value="D:\Music\" />
</appSettings>

擴充建議

• 加入 Play/Pause/Stop/Next/Previous 方法對應 UI 按鈕。
• 實作 INotifyPropertyChanged 暴露 CurrentTrack、Progress 供繫結。
• 支援播放清單儲存/載入 (XML/JSON)。
• 大量檔案時考慮虛擬化清單或背景掃描避免 UI 凍結。