如何用delphi编写控制音量(100分)

如何用delphi编写控制音量

从别处copy的，没试过 看看
mixerSetControlDetails
auxoutsetvolume 是控制CD音量的
waveOutSetVolume 是控制波形的
midiOutSetVolume 是控制FM或者是synthesizer

unit Volume;


interface

uses windows,mmsystem;


type
Tvolume=record
left,right:word;
// 取值范围 0--65535
end;



procedure fillstruct(controlMixerControl;var Cdetails:tMIXERCONTROLDETAILS);

function getpeak(controlMixerControl;var peak:integer):boolean;

function setvolume(controlmixercontrol;
volume:Tvolume):boolean;

function getvolume(controlmixercontrol;
volume:Tvolume):boolean;


var
mcontrols:array of array of array of PMixerControl;
//mixer的数组,单声卡可以不用
fmixerhandle:HMIXER;
//mixer的句柄

implementation

procedure fillstruct(controlMixerControl;var Cdetails:tMIXERCONTROLDETAILS);

begin

Cdetails.cbStruct:=sizeof(cdetails);

cdetails.dwControlID:=Control.dwControlID;

cdetails.cbDetails:=sizeof(integer);

cdetails.hwndOwner:=0;

end;



function getpeak(controlMixerControl;var peak:integer):boolean;

var
details:TMixerControlDetailsSigned;

cdetails:tMIXERCONTROLDETAILS;

begin

Result:=false;

if control.dwControlType<> mixercontrol_controltype_peakmeter then
exit;

cdetails.cChannels:=1;

cdetails.paDetails:=@details;

fillstruct(control,cdetails);

result:=mixerGetControlDetails(fmixerhandle,@cdetails,MIXER_GETCONTROLDETAILSF_VALUE)=0;

end;



function setvolume(controlmixercontrol;
volume:Tvolume):boolean;

var
details:array[0..30] of integer;

cdetails:tMIXERCONTROLDETAILS;

begin

fillstruct(control,cdetails);

cdetails.cChannels:=2;

cdetails.paDetails:=@details;

details[0]:=volume.left;

details[1]:=volume.right;

result:=mixerSetControlDetails(fmixerhandle,@cdetails,MIXER_GETCONTROLDETAILSF_VALUE)=0;

volume.left:=details[0];

volume.right:=details[1];

end;



function getvolume(controlmixercontrol;
volume:Tvolume):boolean;

var
details:array[0..30] of integer;

cdetails:tMIXERCONTROLDETAILS;

begin

fillstruct(control,cdetails);

cdetails.cChannels:=2;

cdetails.paDetails:=@details;

result:=mixerGetControlDetails(fmixerhandle,@cdetails,MIXER_GETCONTROLDETAILSF_VALUE)=0;

volume.left:=details[0];

volume.right:=details[1];

end;



end.


// 调用方法:
procedure TForm1.Button1Click(Sender: TObject);

var s : Tvolume;

kz : Pmixercontrol;

begin

new(kz);
//<------------ 此处一定要分配内存
kz.dwControlID := 0;

s.left := 0;

s.right := 0;

try
setvolume(kz,s);

except
end;


freemem(kz);

end;

waveOutSetVolume