如何：播放声音

  • 项目

更新：2007 年 11 月

此示例演示如何使用平台调用来播放两个 WAV 文件：一个为嵌入的资源，另一个为内容。

若要在 Visual Studio 中实现作为嵌入资源的 WAV 文件，请在“属性”窗格中将其“生成操作”属性设置为“嵌入的资源”。如果在命令行进行编译，请参见 如何：在命令提示符处进行编译 以了解有关编译嵌入资源的信息。

说明：

.NET Compact Framework 3.5 版本支持用 SoundPlayer 来播放声音。有关更多信息，请参见 .NET Compact Framework 中的 SoundPlayer。

此示例定义了 Sound 类，该类通过使用 Windows CE 中的 CoreDll.dll 提供下面的本机代码功能：

  • 使用文件名或流播放声音的平台调用方法声明。

  • 用于在平台调用方法调用中传递参数的位值枚举。

  • Play 方法，用于调用正确的平台调用方法来播放单独的文件或嵌入的资源。

此示例使用名为 Chimes.wav 的声音文件。当包含该声音文件作为嵌入资源时，要通过如下方式为该文件返回资源流：在对 GetManifestResourceStream 的调用中将程序集命名空间添加到原始文件名的前面。

使用平台调用播放声音

  1. 将 Sound 类添加到项目中。

    Public Class Sound
   Private m_soundBytes() As Byte
    Private m_fileName As String

    Public Declare Function WCE_PlaySound Lib "CoreDll.dll" Alias "PlaySound" (ByVal szSound As String, ByVal hMod As IntPtr, ByVal flags As Integer) As Integer
    Public Declare Function WCE_PlaySoundBytes Lib "CoreDll.dll" Alias "PlaySound" (ByVal szSound() As Byte, ByVal hMod As IntPtr, ByVal flags As Integer) As Integer



   Private Enum Flags
      SND_SYNC = &H0 ' play synchronously (default) 
      SND_ASYNC = &H1 ' play asynchronously 
      SND_NODEFAULT = &H2 ' silence (!default) if sound not found 
      SND_MEMORY = &H4 ' pszSound points to a memory file 
      SND_LOOP = &H8 ' loop the sound until next sndPlaySound 
      SND_NOSTOP = &H10 ' don't stop any currently playing sound 
      SND_NOWAIT = &H2000 ' don't wait if the driver is busy 
      SND_ALIAS = &H10000 ' name is a registry alias 
      SND_ALIAS_ID = &H110000 ' alias is a predefined ID 
      SND_FILENAME = &H20000 ' name is file name 
      SND_RESOURCE = &H40004 ' name is resource name or atom 
    End Enum


    ' Construct the Sound object to play sound data from the specified file.
    Public Sub New(ByVal fileName As String)
        m_fileName = fileName
    End Sub


    ' Construct the Sound object to play sound data from the specified stream.
    Public Sub New(ByVal stream As Stream)
        ' read the data from the stream
        m_soundBytes = New Byte(stream.Length) {}
        stream.Read(m_soundBytes, 0, Fix(stream.Length))
    End Sub 'New


    ' Play the sound
    Public Sub Play()
        ' If a file name has been registered, call WCE_PlaySound, 
        ' otherwise call WCE_PlaySoundBytes.
        If Not (m_fileName Is Nothing) Then
            WCE_PlaySound(m_fileName, IntPtr.Zero, Fix(Flags.SND_ASYNC Or Flags.SND_FILENAME))
        Else
            WCE_PlaySoundBytes(m_soundBytes, IntPtr.Zero, Fix(Flags.SND_ASYNC Or Flags.SND_MEMORY))
        End If
    End Sub 
End Class

    public class Sound
{
    private byte[] m_soundBytes;
    private string m_fileName;

    private enum Flags {
        SND_SYNC = 0x0000,  /* play synchronously (default) */
        SND_ASYNC = 0x0001,  /* play asynchronously */
        SND_NODEFAULT = 0x0002,  /* silence (!default) if sound not found */
        SND_MEMORY = 0x0004,  /* pszSound points to a memory file */
        SND_LOOP = 0x0008,  /* loop the sound until next sndPlaySound */
        SND_NOSTOP = 0x0010,  /* don't stop any currently playing sound */
        SND_NOWAIT = 0x00002000, /* don't wait if the driver is busy */
        SND_ALIAS = 0x00010000, /* name is a registry alias */
        SND_ALIAS_ID = 0x00110000, /* alias is a predefined ID */
        SND_FILENAME = 0x00020000, /* name is file name */
        SND_RESOURCE = 0x00040004  /* name is resource name or atom */
    }

    [DllImport("CoreDll.DLL", EntryPoint="PlaySound", SetLastError=true)]
    private extern static int WCE_PlaySound(string szSound, IntPtr hMod, int flags);

    [DllImport("CoreDll.DLL", EntryPoint="PlaySound", SetLastError=true)]
    private extern static int WCE_PlaySoundBytes (byte[] szSound, IntPtr hMod, int flags);

    /// <summary>
    /// Construct the Sound object to play sound data from the specified file.
    /// </summary>
    public Sound (string fileName) {
        m_fileName = fileName;
    }

    /// <summary>
    /// Construct the Sound object to play sound data from the specified stream.
    /// </summary>
    public Sound(Stream stream)    {
        // read the data from the stream
        m_soundBytes = new byte [stream.Length];
        stream.Read(m_soundBytes, 0,(int)stream.Length);
    }

    /// <summary>
    /// Play the sound
    /// </summary>
    public void Play () {
        // if a file name has been registered, call WCE_PlaySound,
        //  otherwise call WCE_PlaySoundBytes
        if (m_fileName != null)
            WCE_PlaySound(m_fileName, IntPtr.Zero, (int) (Flags.SND_ASYNC | Flags.SND_FILENAME));
        else
            WCE_PlaySoundBytes (m_soundBytes, IntPtr.Zero, (int) (Flags.SND_ASYNC | Flags.SND_MEMORY));
    }
}

  2. 添加用于创建 Sound 类的实例和播放文件的方法，例如，在某按钮的 Click 事件中。

    ' To return a Stream object associated with an embedded
' resource, you must prepend the namespace to the original
' name of the file in the project.
Private Sub btnEmbedded_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnEmbedded.Click
    Dim sound As New Sound([Assembly].GetExecutingAssembly().GetManifestResourceStream("SoundSample.chimes.wav"))
    sound.Play()
End Sub 


Private Sub btnFile_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnFile.Click
    Dim sound As New Sound("Program Files\SoundSample\chord.wav")
    sound.Play()
End Sub

    // To return a Stream object associated with an embedded
// resource, you must prepend the namespace to the original
// name of the file in the project.
private void btnEmbedded_Click(object sender, System.EventArgs e) {
    Sound sound = new Sound (Assembly.GetExecutingAssembly().GetManifestResourceStream("SoundSample.chimes.wav"));
    sound.Play();
}

private void btnFile_Click(object sender, System.EventArgs e) {
    Sound sound = new Sound ("Program Files\\SoundSample\\chord.wav");
    sound.Play();
}

编译代码

此示例需要引用下面的命名空间：

请参见

概念

.NET Compact Framework 帮助主题

其他资源

.NET Compact Framework 中的互操作性