利用winmm控制音量的小例子

bool     WINAPI     SetVolume( long     dev, long     vol); //设置设备的音量,dev=0主音量，1WAVE     ,2MIDI     ,3     LINE     IN

unsigned     WINAPI     GetVolume( int     dev); //得到设备的音量dev=0主音量，1WAVE     ,2MIDI     ,3     LINE     IN

//显示音量
void controlsoundvolumeDialog::ShowVolume()
{
         //获得当前系统音量
        unsigned int currentVolume=GetVolume(m_decType);
        m_sliderVolume->SetValue(currentVolume);
         //数字化显示音量
        wxString volumeLabelString = wxString::Format(wxT( "%i"),currentVolume);
        m_staticTextVolume->SetLabel(volumeLabelString);

}
//静音模式
void controlsoundvolumeDialog::IsMute( wxCommandEvent& event )
{
         //判断是否选择静音
         if (m_checkBoxMute->GetValue())
        {
                SetVolume(m_decType,0);
        }
         else
        {
                 int volume=m_sliderVolume->GetValue();
                SetVolume(m_decType,volume);
        }
}

//改变音量
void controlsoundvolumeDialog::ChangeSoundVolume( wxScrollEvent& event )
{
         int volume=m_sliderVolume->GetValue();
         //设置音量,
        SetVolume(m_decType,volume);
         //数字化显示音量
        wxString volumeLabelString = wxString::Format(wxT( "%i"),volume);
        m_staticTextVolume->SetLabel(volumeLabelString);
}

//改变选择音量类型
void controlsoundvolumeDialog::ChangeVolumeType( wxCommandEvent& event )
{
         int decType=m_choiceVolumeType->GetCurrentSelection();
         switch (decType)
        {
         case 0:
                m_decType=0;
                 break;
         case 1:
                m_decType=1;
                 break;
         case 2:
                m_decType=2;
                 break;
         default:
                m_decType=0;
                 break;
        }
        ShowVolume();
}