简单的 VB.NET MIDI & 波形播放类

引言

这是一个简单的类，用于在您的 VB.NET 应用程序中播放 MIDI 和波形文件。

使用代码

将一个新的类文件添加到您的项目中，并将代码复制到其中。 引用 DirectX7 COM 对象。

Imports System
Imports DxVBLib

Public Class SoundPlayer

    ' Basic Wave and MIDI Player Class for VB.net 1.1
    ' Requires COM-Object : DirectX7 

    Private Declare Function mciSendString Lib "Winmm.dll" Alias "mciSendStringA" _
    (ByVal lpstrCommand As String, ByVal lpstrReturnString As String, _
    ByVal uReturnLength As Long, ByVal hwndCallback As Long) As Long
    
    Private File As String

    Private m_dx As New DirectX7
    Private m_ds As DirectSound

    Public Sub New(ByVal strFileName As String)

        Me.File = strFileName

    End Sub

    ' To show what file is selected (if needed)
    Public ReadOnly Property FileName() As String

        Get
            Return File
        End Get

    End Property

    Public Function PlaySound() As Boolean

        If InitAudio() = True Then
            If PlayFile() = True Then
                Return True
            Else
                Return False
            End If
        Else
            ' Audiohardware not found
            ' exit here
            Return False
        End If

    End Function

    Public Function StopSound() As Boolean

        StopFile()

    End Function

    Private Function PlayFile() As Boolean

        Dim lRet As Long

        Try
            StopFile()

            lRet = mciSendString("open " & Me.File & " alias track", "", 0, 0)
            lRet = mciSendString("play track", "", 0, 0)
            PlayFile = (lRet = 0)

        Catch ex As Exception
            Return False
        End Try

        Return True

    End Function

    Public Function CloseAudio()

        mciSendString("close all", 0, 0, 0)

    End Function

    Private Function StopFile() As Boolean

        Dim lRet As Long

        Try
            lRet = mciSendString("stop track", "", 0, 0)
            lRet = mciSendString("close track", "", 0, 0)
            Return True
        Catch ex As Exception
            Return False
        End Try

    End Function

    Private Function InitAudio() As Boolean

        m_ds = m_dx.DirectSoundCreate("")
        If Err.Number <> 0 Then
            Return False
        Else
            Return True
        End If

    End Function

End Class

在您的应用程序中，像这样播放声音

Dim Sound As New SoundPlayer(".\sound\testmidi.mid")
Sound.PlaySound()

或

Sound.StopSound()

停止播放。

Sound.FileName 显示在声明时提供给类的文件名。

我没有测试过，但我相信它也适用于 DX8 或 DX9。 并且始终记住：这段代码是为初学者提供的，用于演示如何播放 MIDI 和波形文件。 该类只播放每个文件一次。 不循环...