VB6 利用SendMessage控制音量

Private Declare Function SendMessage Lib "user32.dll" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
Private Const WM_APPCOMMAND As Long = &H319
Private Const APPCOMMAND_VOLUME_UP As Long = 10
Private Const APPCOMMAND_VOLUME_DOWN As Long = 9
Private Const APPCOMMAND_VOLUME_MUTE As Long = 8

Private Sub Command1_Click()
  '音量增加
  SendMessage Me.hwnd, WM_APPCOMMAND, &H30292, APPCOMMAND_VOLUME_UP * &H10000
End Sub

Private Sub Command2_Click()
  '音量減少
  SendMessage Me.hwnd, WM_APPCOMMAND, &H30292, APPCOMMAND_VOLUME_DOWN * &H10000
End Sub

Private Sub Command3_Click()
  '靜音
  SendMessage Me.hwnd, WM_APPCOMMAND, &H200EB0, APPCOMMAND_VOLUME_MUTE * &H10000
End Sub