控制系统音量及声道---------------------------- ---------------------------三个TrackBar的属性设置:Max:=255;Frequency:=16; uses mmsystem; procedure TForm1.TrackBar1Change(Sender: TObject); /////////音量 var t,v:Longint; begin // if a=0 then Exit; t:=TrackBar1.Position; v:=(t shl 8)or(t shl 24); waveOutSetVolume(0,v); end;procedure TForm1.TrackBar2Change(Sender: TObject); ////左声道 var t,v:Longint; begin t:=TrackBar2.Position; waveOutGetVolume(0,@v); v:=v and $ffff0000 or (t shl 8); waveOutSetVolume(0,v); end;procedure TForm1.TrackBar3Change(Sender: TObject); /////右声道 var t,v:Longint; begin t:=TrackBar3.Position; waveOutGetVolume(0,@v); v:=v and $0000ffff or (t shl 24); waveOutSetVolume(0,v); end;procedure TForm1.FormCreate(Sender: TObject); //////////获得当前音量值 var v:longint; begin waveOutGetVolume(0,@v); TrackBar2.Position:=hi(v); TrackBar3.Position:=hi(v shr 16); if hi(v)>hi(v shr 16) then TrackBar1.Position:=hi(v) else TrackBar1.Position:=hi(v shr 16); end;
FrmMain.MediaPlayer.settings.volume = iValuedephi不会
---------------------------三个TrackBar的属性设置:Max:=255;Frequency:=16; uses mmsystem;
procedure TForm1.TrackBar1Change(Sender: TObject); /////////音量
var
t,v:Longint;
begin
// if a=0 then Exit;
t:=TrackBar1.Position;
v:=(t shl 8)or(t shl 24);
waveOutSetVolume(0,v);
end;procedure TForm1.TrackBar2Change(Sender: TObject); ////左声道
var
t,v:Longint;
begin
t:=TrackBar2.Position;
waveOutGetVolume(0,@v);
v:=v and $ffff0000 or (t shl 8);
waveOutSetVolume(0,v);
end;procedure TForm1.TrackBar3Change(Sender: TObject); /////右声道
var
t,v:Longint;
begin
t:=TrackBar3.Position;
waveOutGetVolume(0,@v);
v:=v and $0000ffff or (t shl 24);
waveOutSetVolume(0,v);
end;procedure TForm1.FormCreate(Sender: TObject); //////////获得当前音量值
var
v:longint;
begin
waveOutGetVolume(0,@v);
TrackBar2.Position:=hi(v);
TrackBar3.Position:=hi(v shr 16);
if hi(v)>hi(v shr 16) then
TrackBar1.Position:=hi(v)
else
TrackBar1.Position:=hi(v shr 16);
end;
-------------------------uses
MMSystem;const
MCI_SETAUDIO = $0873;
MCI_DGV_SETAUDIO_VOLUME = $4002;
MCI_DGV_SETAUDIO_ITEM = $00800000;
MCI_DGV_SETAUDIO_VALUE = $01000000;
MCI_DGV_STATUS_VOLUME = $4019;type MCI_DGV_SETAUDIO_PARMS = record
dwCallback: DWORD;
dwItem: DWORD;
dwValue: DWORD;
dwOver: DWORD;
lpstrAlgorithm: PChar;
lpstrQuality: PChar; end;type MCI_STATUS_PARMS = record
dwCallback: DWORD;
dwReturn: DWORD;
dwItem: DWORD;
dwTrack: DWORD; end; {设置音量,范围 0 - 1000}procedure MPSetVolume(MP: TMediaPlayer; Volume: Integer) ;
var
p: MCI_DGV_SETAUDIO_PARMS;
begin
p.dwCallback := 0;
p.dwItem := MCI_DGV_SETAUDIO_VOLUME;
p.dwValue := Volume;
p.dwOver := 0;
p.lpstrAlgorithm := nil;
p.lpstrQuality := nil;
mciSendCommand(MP.DeviceID, MCI_SETAUDIO, MCI_DGV_SETAUDIO_VALUE or MCI_DGV_SETAUDIO_ITEM, Cardinal(@p)) ;
end; {获得音量,范围 0 - 1000}function MPGetVolume(MP: TMediaPlayer): Integer;
var
p: MCI_STATUS_PARMS;
begin
p.dwCallback := 0;
p.dwItem := MCI_DGV_STATUS_VOLUME;
mciSendCommand(MP.DeviceID, MCI_STATUS, MCI_STATUS_ITEM, Cardinal(@p)) ;
Result := p.dwReturn;
end; //用法:在Delphi窗体中放入一个TMediaPlayer("MediaPlayer1")和一个TScrollBar("ScrollBar1")。 //在窗体的OnCreate事件中,设置滚动条并且将一个媒体文件导入到MediaPlayer中: procedure TMediaPlayerForm.FormCreate(Sender: TObject) ;
begin
ScrollBar1.Min := 0;
ScrollBar1.Max := 1000;
ScrollBar1.Position := MPGetVolume(MediaPlayer1);
MediaPlayer1.Close;
MediaPlayer1.FileName:='c:\favorite.mp3';
MediaPlayer1.Open;end;//处理滚动条的OnChange事件(设置Media Player的音量):procedure TMediaPlayerForm.ScrollBar1Change(Sender: TObject) ;
begin
MPSetVolume(MediaPlayer1, ScrollBar1.Position) ;
end;
代码我测试过了,没问题,非常感谢