SoundPlayer 类提供了加载和播放 .wav 文件的简单界面。SoundPlayer 类支持从文件路径、URL、包含 .wav 文件的 Stream 或包含 .wav 文件的嵌入资源中加载 .wav 文件。
要使用 SoundPlayer 类播放声音，请用 .wav 文件的路径配置 SoundPlayer 并调用某个播放方法。可以使用某个构造函数或通过设置 SoundLocation 或 Stream 属性来标识要播放的 .wav 文件。可以在播放前使用某个加载方法加载文件，或者将加载推迟到调用某个播放方法时。被配置为从 Stream 或 URL 中加载 .wav 文件的 SoundPlayer 必须在播放开始前将 .wav 文件加载到内存中。
可以同步或异步地加载或播放 .wav 文件。如果调用同步加载或播放方法，调用线程将一直等到方法返回，这可能会导致绘制和其他事件中断。调用异步加载或播放方法则允许调用线程继续执行，而不会中断。How to: Run an Operation in the Background.’ xml:space=”preserve”>有关异步方法调用的更多信息，请参见如何：在后台运行操作。
当 SoundPlayer 加载完 .wav 文件后，它会引发 LoadCompleted 事件。可以检查事件处理程序中的 AsyncCompletedEventArgs，确定加载是成功还是失败。当音频源设置为新文件路径或 URL 时，引发 SoundLocationChanged 事件。当音频源设置为新 Stream 时，引发 StreamChanged 事件。
说明：
SoundPlayer 类不能播放其他文件类型，如 .wma 或 .mp3。如果想播放其他文件类型，可以使用 Windows Media Player 控件。有关更多信息，请参见 Windows 媒体播放器 SDK 中的 Using the Windows Media Player Control in a .NET Framework Solution（在 .NET 解决方案中使用 Windows 媒体播放器控件）和 Windows Media Player Object Model Reference for Visual Basic .NET and C#（Visual Basic .NET 和 C# 的 Windows 媒体播放器对象模型参考）。
public partial class SoundTestForm : Form
{
private System.Windows.Forms.Label label1;
private System.Windows.Forms.TextBox filepathTextbox;
private System.Windows.Forms.Button playOnceSyncButton;
private System.Windows.Forms.Button playOnceAsyncButton;
private System.Windows.Forms.Button playLoopAsyncButton;
private System.Windows.Forms.Button selectFileButton;
private System.Windows.Forms.Button stopButton;
private System.Windows.Forms.StatusBar statusBar;
private System.Windows.Forms.Button loadSyncButton;
private System.Windows.Forms.Button loadAsyncButton;
private SoundPlayer player;
public SoundTestForm()
{
// Initialize Forms Designer generated code.
InitializeComponent();
// Disable playback controls until a valid .wav file
// is selected.
EnablePlaybackControls(false);
// Set up the status bar and other controls.
InitializeControls();
// Set up the SoundPlayer object.
InitializeSound();
}
// Sets up the status bar and other controls.
private void InitializeControls()
{
// Set up the status bar.
StatusBarPanel panel = new StatusBarPanel();
panel.BorderStyle = StatusBarPanelBorderStyle.Sunken;
panel.Text = “Ready.”;
panel.AutoSize = StatusBarPanelAutoSize.Spring;
this.statusBar.ShowPanels = true;
this.statusBar.Panels.Add(panel);
}
// Sets up the SoundPlayer object.
private void InitializeSound()
{
// Create an instance of the SoundPlayer class.
player = new SoundPlayer();
// Listen for the LoadCompleted event.
player.LoadCompleted += new AsyncCompletedEventHandler(player_LoadCompleted);
// Listen for the SoundLocationChanged event.
player.SoundLocationChanged += new EventHandler(player_LocationChanged);
}
private void selectFileButton_Click(object sender,
System.EventArgs e)
{
// Create a new OpenFileDialog.
OpenFileDialog dlg = new OpenFileDialog();
// Make sure the dialog checks for existence of the
// selected file.
dlg.CheckFileExists = true;
// Allow selection of .wav files only.
dlg.Filter = “WAV files (*.wav)|*.wav”;
dlg.DefaultExt = “.wav”;
// Activate the file selection dialog.
if (dlg.ShowDialog() == DialogResult.OK)
{
// Get the selected file’s path from the dialog.
this.filepathTextbox.Text = dlg.FileName;
// Assign the selected file’s path to
// the SoundPlayer object.
player.SoundLocation = filepathTextbox.Text;
}
}
// Convenience method for setting message text in
// the status bar.
private void ReportStatus(string statusMessage)
{
// If the caller passed in a message…
if ((statusMessage != null) && (statusMessage != String.Empty))
{
// …post the caller’s message to the status bar.
this.statusBar.Panels[0].Text = statusMessage;
}
}
// Enables and disables play controls.
private void EnablePlaybackControls(bool enabled)
{
this.playOnceSyncButton.Enabled = enabled;
this.playOnceAsyncButton.Enabled = enabled;
this.playLoopAsyncButton.Enabled = enabled;
this.stopButton.Enabled = enabled;
}
private void filepathTextbox_TextChanged(object sender,
EventArgs e)
{
// Disable playback controls until the new .wav is loaded.
EnablePlaybackControls(false);
}
private void loadSyncButton_Click(object sender,
System.EventArgs e)
{
// Disable playback controls until the .wav is
// successfully loaded. The LoadCompleted event
// handler will enable them.
EnablePlaybackControls(false);
try
{
// Assign the selected file’s path to
// the SoundPlayer object.
player.SoundLocation = filepathTextbox.Text;
// Load the .wav file.
player.Load();
}
catch (Exception ex)
{
ReportStatus(ex.Message);
}
}
private void loadAsyncButton_Click(System.Object sender,
System.EventArgs e)
{
// Disable playback controls until the .wav is
// successfully loaded. The LoadCompleted event
// handler will enable them.
EnablePlaybackControls(false);
try
{
// Assign the selected file’s path to
// the SoundPlayer object.
player.SoundLocation = this.filepathTextbox.Text;
// Load the .wav file.
player.LoadAsync();
}
catch (Exception ex)
{
ReportStatus(ex.Message);
}
}
// Synchronously plays the selected .wav file once.
// If the file is large, UI response will be visibly
// affected.
private void playOnceSyncButton_Click(object sender,
System.EventArgs e)
{
ReportStatus(“Playing .wav file synchronously.”);
player.PlaySync();
ReportStatus(“Finished playing .wav file synchronously.”);
}
// Asynchronously plays the selected .wav file once.
private void playOnceAsyncButton_Click(object sender,
System.EventArgs e)
{
ReportStatus(“Playing .wav file asynchronously.”);
player.Play();
}
// Asynchronously plays the selected .wav file until the user
// clicks the Stop button.
private void playLoopAsyncButton_Click(object sender,
System.EventArgs e)
{
ReportStatus(“Looping .wav file asynchronously.”);
player.PlayLooping();
}
// Stops the currently playing .wav file, if any.
private void stopButton_Click(System.Object sender,
System.EventArgs e)
{
player.Stop();
ReportStatus(“Stopped by user.”);
}
// Handler for the LoadCompleted event.
private void player_LoadCompleted(object sender,
AsyncCompletedEventArgs e)
{
string message = String.Format(“LoadCompleted: {0}”,
this.filepathTextbox.Text);
ReportStatus(message);
EnablePlaybackControls(true);
}
// Handler for the SoundLocationChanged event.
private void player_LocationChanged(object sender, EventArgs e)
{
string message = String.Format(“SoundLocationChanged: {0}”,
player.SoundLocation);
ReportStatus(message);
}
//#region Windows Form Designer generated code
private void InitializeComponent()
{
this.filepathTextbox = new System.Windows.Forms.TextBox();
this.selectFileButton = new System.Windows.Forms.Button();
this.label1 = new System.Windows.Forms.Label();
this.loadSyncButton = new System.Windows.Forms.Button();
this.playOnceSyncButton = new System.Windows.Forms.Button();
this.playOnceAsyncButton = new System.Windows.Forms.Button();
this.stopButton = new System.Windows.Forms.Button();
this.playLoopAsyncButton = new System.Windows.Forms.Button();
this.statusBar = new System.Windows.Forms.StatusBar();
this.loadAsyncButton = new System.Windows.Forms.Button();
this.SuspendLayout();
//
// filepathTextbox
//
this.filepathTextbox.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left) | System.Windows.Forms.AnchorStyles.Right)));
this.filepathTextbox.Location = new System.Drawing.Point(7, 25);
this.filepathTextbox.Name = “filepathTextbox”;
this.filepathTextbox.Size = new System.Drawing.Size(263, 20);
this.filepathTextbox.TabIndex = 1;
this.filepathTextbox.Text = “”;
this.filepathTextbox.TextChanged += new System.EventHandler(this.filepathTextbox_TextChanged);
//
// selectFileButton
//
this.selectFileButton.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Right)));
this.selectFileButton.Location = new System.Drawing.Point(276, 25);
this.selectFileButton.Name = “selectFileButton”;
this.selectFileButton.Size = new System.Drawing.Size(23, 21);
this.selectFileButton.TabIndex = 2;
this.selectFileButton.Text = “…”;
this.selectFileButton.Click += new System.EventHandler(this.selectFileButton_Click);
//
// label1
//
this.label1.Location = new System.Drawing.Point(7, 7);
this.label1.Name = “label1”;
this.label1.Size = new System.Drawing.Size(145, 17);
this.label1.TabIndex = 3;
this.label1.Text = “.wav path or URL:”;
//
// loadSyncButton
//
this.loadSyncButton.Location = new System.Drawing.Point(7, 53);
this.loadSyncButton.Name = “loadSyncButton”;
this.loadSyncButton.Size = new System.Drawing.Size(142, 23);
this.loadSyncButton.TabIndex = 4;
this.loadSyncButton.Text = “Load Synchronously”;
this.loadSyncButton.Click += new System.EventHandler(this.loadSyncButton_Click);
//
// playOnceSyncButton
//
this.playOnceSyncButton.Location = new System.Drawing.Point(7, 86);
this.playOnceSyncButton.Name = “playOnceSyncButton”;
this.playOnceSyncButton.Size = new System.Drawing.Size(142, 23);
this.playOnceSyncButton.TabIndex = 5;
this.playOnceSyncButton.Text = “Play Once Synchronously”;
this.playOnceSyncButton.Click += new System.EventHandler(this.playOnceSyncButton_Click);
//
// playOnceAsyncButton
//
this.playOnceAsyncButton.Location = new System.Drawing.Point(149, 86);
this.playOnceAsyncButton.Name = “playOnceAsyncButton”;
this.playOnceAsyncButton.Size = new System.Drawing.Size(147, 23);
this.playOnceAsyncButton.TabIndex = 6;
this.playOnceAsyncButton.Text = “Play Once Asynchronously”;
this.playOnceAsyncButton.Click += new System.EventHandler(this.playOnceAsyncButton_Click);
//
// stopButton
//
this.stopButton.Location = new System.Drawing.Point(149, 109);
this.stopButton.Name = “stopButton”;
this.stopButton.Size = new System.Drawing.Size(147, 23);
this.stopButton.TabIndex = 7;
this.stopButton.Text = “Stop”;
this.stopButton.Click += new System.EventHandler(this.stopButton_Click);
//
// playLoopAsyncButton
//
this.playLoopAsyncButton.Location = new System.Drawing.Point(7, 109);
this.playLoopAsyncButton.Name = “playLoopAsyncButton”;
this.playLoopAsyncButton.Size = new System.Drawing.Size(142, 23);
this.playLoopAsyncButton.TabIndex = 8;
this.playLoopAsyncButton.Text = “Loop Asynchronously”;
this.playLoopAsyncButton.Click += new System.EventHandler(this.playLoopAsyncButton_Click);
//
// statusBar
//
this.statusBar.Location = new System.Drawing.Point(0, 146);
this.statusBar.Name = “statusBar”;
this.statusBar.Size = new System.Drawing.Size(306, 22);
this.statusBar.SizingGrip = false;
this.statusBar.TabIndex = 9;
this.statusBar.Text = “(no status)”;
//
// loadAsyncButton
//
this.loadAsyncButton.Location = new System.Drawing.Point(149, 53);
this.loadAsyncButton.Name = “loadAsyncButton”;
this.loadAsyncButton.Size = new System.Drawing.Size(147, 23);
this.loadAsyncButton.TabIndex = 10;
this.loadAsyncButton.Text = “Load Asynchronously”;
this.loadAsyncButton.Click += new System.EventHandler(this.loadAsyncButton_Click);
//
// SoundTestForm
//
this.ClientSize = new System.Drawing.Size(306, 168);
this.Controls.Add(this.loadAsyncButton);
this.Controls.Add(this.statusBar);
this.Controls.Add(this.playLoopAsyncButton);
this.Controls.Add(this.stopButton);
this.Controls.Add(this.playOnceAsyncButton);
this.Controls.Add(this.playOnceSyncButton);
this.Controls.Add(this.loadSyncButton);
this.Controls.Add(this.label1);
this.Controls.Add(this.selectFileButton);
this.Controls.Add(this.filepathTextbox);
this.MinimumSize = new System.Drawing.Size(310, 165);
this.Name = “SoundTestForm”;
this.SizeGripStyle = System.Windows.Forms.SizeGripStyle.Show;
this.Text = “Sound API Test Form”;
this.ResumeLayout(false);
}
