Mediaplayer怎么切换声道？(100分)

谢谢回答

procedure SwitchChinnel(MPlayer:TMediaplayer;ChSet:TChannels);
var
s: MCI_DGV_SETAUDIO_PARMS ;
begin

mciSendCommand(MPlayer.DeviceID,MCI_SETAUDIO,MCI_SET_OFF,integer(@s));
case ChSet of
ch_stereo:
s.dwValue:=MCI_DGV_SETAUDIO_SOURCE_STEREO;
//Á¢ÌåÉùÓÃÕâ¾ä

接上
ch_left:
s.dwValue:=MCI_DGV_SETAUDIO_SOURCE_LEFT;
//×óÉùµÀÔ´
ch_right:
s.dwValue:=MCI_DGV_SETAUDIO_SOURCE_RIGHT;
//ÓÒÉùµÀÔ´
end;

s.dwItem:=MCI_DGV_SETAUDIO_SOURCE;
mciSendCommand(MPlayer.DeviceID,MCI_SETAUDIO, MCI_DGV_SETAUDIO_VALUE or MCI_DGV_SETAUDIO_ITEM ,integer(@s));
mciSendCommand(MPlayer.DeviceID,MCI_SETAUDIO, MCI_SET_ON,integer(@s));
end;

接受答案了.

TChannels 我在用上面的那个时，怎么会出现不能找出tchannels