一段设置和取消windows静音效果的Delphi代码

看到完美mm在windows版提问求这么一个dos命令，发现没有，于是自己摘录了以下代码编译了一个控制台程序

unit Unit1;
interface
uses MMSystem, Dialogs;
type TDeviceName = (Master, Microphone, WaveOut, Synth);
procedure SetVolumeMute(DN:TDeviceName; Value:Boolean);
implementation
procedure SetVolumeMute(DN:TDeviceName; Value:Boolean);
var
hMix: HMIXER;
mxlc: MIXERLINECONTROLS;
mxcd: TMIXERCONTROLDETAILS;
vol: TMIXERCONTROLDETAILS_UNSIGNED;
mxc: MIXERCONTROL;
mxl: TMixerLine;
intRet: Integer;
nMixerDevs: Integer;
mcdMute: MIXERCONTROLDETAILS_BOOLEAN;
begin
// Check if Mixer is available
nMixerDevs := mixerGetNumDevs();
if (nMixerDevs < 1) then
begin
Exit;
end;
// open the mixer
intRet := mixerOpen(@hMix, 0, 0, 0, 0);
if intRet = MMSYSERR_NOERROR then
begin
case DN of
Master : mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_DST_SPEAKERS;
Microphone :
mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_SRC_MICROPHONE;
WaveOut : mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_SRC_WAVEOUT;
Synth : mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_SRC_SYNTHESIZER;
end;
mxl.cbStruct := SizeOf(mxl);
// mixerline info
intRet := mixerGetLineInfo(hMix, @mxl, MIXER_GETLINEINFOF_COMPONENTTYPE);
if intRet = MMSYSERR_NOERROR then
begin
FillChar(mxlc, SizeOf(mxlc),0);
mxlc.cbStruct := SizeOf(mxlc);
mxlc.dwLineID := mxl.dwLineID;
mxlc.dwControlType := MIXERCONTROL_CONTROLTYPE_MUTE;
mxlc.cControls := 1;
mxlc.cbmxctrl := SizeOf(mxc);
mxlc.pamxctrl := @mxc;
// Get the mute control
intRet := mixerGetLineControls(hMix, @mxlc, MIXER_GETLINECONTROLSF_ONEBYTYPE);
if intRet = MMSYSERR_NOERROR then
begin
FillChar(mxcd, SizeOf(mxcd),0);
mxcd.cbStruct := SizeOf(TMIXERCONTROLDETAILS);
mxcd.dwControlID := mxc.dwControlID;
mxcd.cChannels := 1;
mxcd.cbDetails := SizeOf(MIXERCONTROLDETAILS_BOOLEAN);
mxcd.paDetails := @mcdMute;
// Set and UnSet mute
mcdMute.fValue := Ord(Value);
intRet := mixerSetControlDetails(hMix, @mxcd, MIXER_SETCONTROLDETAILSF_VALUE);
if intRet <> MMSYSERR_NOERROR then
ShowMessage('SetControlDetails Error');
end
else
ShowMessage('GetLineInfo Error');
end;
intRet := mixerClose(hMix);
end;
end;
end.