我是琳琳，刚才提问有关音量问题的人。如果用一个TrackBar控制左右音道如何解决？

呵呵，不想用控件，可以参考它的源代码：unit BUSoundControl;{*******************************************************}
{                                                       }
{   BUPack Component Package                            }
{   From BuyPin Software - http://www.buypin.com        }
{                                                       }
{   Copyright (c) 1998,2000 S閎astien Buysse            }
{                                                       }
{*******************************************************}{$ObjExportAll On}interfaceuses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, BUTypes,
  MMSystem;type
  TBUSoundValue = class(TPersistent)
  private
    FHandle: Integer;
    FOnRefresh: TNotifyEvent;
    FOnUpdate: TNotifyEvent;
    FBalance,FVolume:Integer;
    function GetBalance: TBalance;
    function GetVolume: byte;
    procedure SetBalance(const Value: TBalance);
    procedure SetVolume(const Value: byte);
  protected
    property OnRefresh:TNotifyEvent read FOnRefresh write FOnRefresh;
    property OnUpdate:TNotifyEvent read FOnUpdate write FOnUpdate;
    property Handle:Integer read FHandle write FHandle;
    procedure SetValue(Vol:TVolumeRec);
    function GetValue:TVolumeRec;
  public
    constructor Create;
  published
    property Volume:byte read GetVolume write SetVolume stored false;
    property Balance:TBalance read GetBalance write SetBalance stored false;
  end;  TBUSoundControl = class(TComponent)
  private
    FMidi: TBUSoundValue;
    FCd: TBUSoundValue;
    FWave: TBUSoundValue;
    FLastError: Integer;    procedure OnCdRefresh(Sender: TObject);
    procedure OnWaveRefresh(Sender: TObject);
    procedure OnMidiRefresh(Sender: TObject);
    procedure OnCdUpdate(Sender: TObject);
    procedure OnWaveUpdate(Sender: TObject);
    procedure OnMidiUpdate(Sender: TObject);
  protected
  public
    constructor Create(AOwner: TComponent);override;
    destructor Destroy;override;
    property LastError:Integer read FLastError;
  published
    property Wave:TBUSoundValue read FWave write FWave;
    property Midi:TBUSoundValue read FMidi write FMidi;
    property Cd:TBUSoundValue read FCd write FCd;
  end;implementation{**********************************************************}
constructor TBUSoundControl.Create(AOwner: TComponent);
var
  AuxCaps     : TAuxCaps;
  WaveOutCaps : TWaveOutCaps;
  MidiOutCaps : TMidiOutCaps;
  i:Integer;
begin
  inherited;
  FLastError:=0;

  FMidi:=TBUSoundValue.Create;
  FCd:=TBUSoundValue.Create;
  FWave:=TBUSoundValue.Create;  FCd.OnRefresh:=OnCdRefresh;
  FWave.OnRefresh:=OnWaveRefresh;
  FMidi.OnRefresh:=OnMidiRefresh;  FCd.OnUpdate:=OnCdUpdate;
  FWave.OnUpdate:=OnWaveUpdate;
  FMidi.OnUpdate:=OnMidiUpdate;  for i:=0 to auxGetNumDevs-1 do
  begin
    auxGetDevCaps(I, @AuxCaps, SizeOf(AuxCaps));
    if (AuxCaps.dwSupport and AUXCAPS_VOLUME) <> 0 then
    begin
      FCd.Handle:=i;
      break;
    end;
  end;  for i:=0 to waveOutGetNumDevs-1 do
  begin
    waveOutGetDevCaps(I, @WaveOutCaps, SizeOf(WaveOutCaps));
    if (WaveOutCaps.dwSupport and WAVECAPS_VOLUME) <> 0 then
    begin
      FWave.Handle:=i;
      break;
    end;
  end;  for i:=0 to midiOutGetNumDevs-1 do
  begin
    MidiOutGetDevCaps(i, @MidiOutCaps, SizeOf(MidiOutCaps));
    if (MidiOutCaps.dwSupport and MIDICAPS_VOLUME) <> 0 then
    begin
      FMidi.Handle:=I;
      break;
    end;
  end;
end;
{**********************************************************}
destructor TBUSoundControl.Destroy;
begin
  FMidi.Free;
  FCd.Free;
  FWave.Free;
  inherited;
end;
{**********************************************************}
procedure TBUSoundControl.OnCdRefresh(Sender: TObject);
var
  Vol:TVolumeRec;
begin
  with Sender as TBUSoundValue do
  begin
    FLastError:=AuxGetVolume(Handle,@Vol.LongVolume);
    if FLastError=MMSYSERR_NOERROR then SetValue(Vol);
  end;
end;
{**********************************************************}
procedure TBUSoundControl.OnCdUpdate(Sender: TObject);
var
  Vol:TVolumeRec;
begin
  with Sender as TBUSoundValue do
  begin
    Vol:=GetValue;
    FLastError:=AuxSetVolume(Handle,Vol.LongVolume);
  end;
end;
{**********************************************************}
procedure TBUSoundControl.OnMidiRefresh(Sender: TObject);
var
  Vol:TVolumeRec;
begin
  with Sender as TBUSoundValue do
  begin
    FLastError:=MidiOutGetVolume(Handle,@Vol.LongVolume);
    if FLastError=MMSYSERR_NOERROR then SetValue(Vol);
  end;
end;
{**********************************************************}
procedure TBUSoundControl.OnMidiUpdate(Sender: TObject);
var
  Vol:TVolumeRec;
begin
  with Sender as TBUSoundValue do
  begin
    Vol:=GetValue;
    FLastError:=MidiOutSetVolume(Handle,Vol.LongVolume);
  end;
end;
{**********************************************************}
procedure TBUSoundControl.OnWaveRefresh(Sender: TObject);
var
Vol:TVolumeRec;
begin
  with Sender as TBUSoundValue do
  begin
    FLastError:=waveOutGetVolume(Handle,@Vol.LongVolume);
    if FLastError=MMSYSERR_NOERROR then SetValue(Vol);
  end;
end;
{**********************************************************}
procedure TBUSoundControl.OnWaveUpdate(Sender: TObject);
var
  Vol:TVolumeRec;
begin
  with Sender as TBUSoundValue do
  begin
    Vol:=GetValue;
    FLastError:=WaveOutSetVolume(Handle,Vol.LongVolume);
  end;
end;
{**********************************************************}
{ TBUSoundValue }
{**********************************************************}
constructor TBUSoundValue.Create;
begin
  FHandle:=-1;
end;
{**********************************************************}
function TBUSoundValue.GetBalance: TBalance;
begin
  if FHandle=-1 then result:=0
  else
  begin
    if Assigned(FOnRefresh) then FOnRefresh(self);
    result:=FBalance;
  end;
end;
{**********************************************************}
function TBUSoundValue.GetValue: TVolumeRec;
begin
  Result.LeftVolume:=round(((FVolume*FBalance)/100)) shl 9;
  Result.RightVolume:=round(((FVolume*(100-FBalance))/100)) shl 9;
end;
{**********************************************************}
function TBUSoundValue.GetVolume: byte;
begin
  if FHandle=-1 then result:=0
  else
  begin
    if Assigned(FOnRefresh) then FOnRefresh(self);
    result:=FVolume;
  end;
end;
{**********************************************************}
procedure TBUSoundValue.SetBalance(const Value: TBalance);
begin
  if FHandle<>-1 then
  begin
    FBalance:=Value;
    if Assigned(FOnUpdate) then FOnUpdate(self);
  end;
end;
{**********************************************************}
procedure TBUSoundValue.SetValue(Vol: TVolumeRec);
var
Total:double;
begin
  FVolume:=(Vol.LeftVolume+Vol.RightVolume) shr 9;
  Total:=(Vol.LeftVolume+Vol.RightVolume) / 100;
  if Total<>0 then
    FBalance:=Round(Vol.LeftVolume/Total);
end;
{**********************************************************}
procedure TBUSoundValue.SetVolume(const Value: byte);
begin
  if FHandle<>-1 then
  begin
    FVolume:=Value;
    if Assigned(FOnUpdate) then FOnUpdate(self);
  end;
end;
{**********************************************************}
end.
http://www.vbapi.com/ref/funcc.html你去这里看看阿～～你的操作系统是什么？？？是不是ｗｉｎ２０００？？？
Faint~~~~~失败～～好像2000不支持这个ＡＰＩ了～～～我这里没有ＭＳＤＮ～～不知道怎么办了～～Ｓｏｒｒｙ～～

调试易

我是琳琳，刚才提问有关音量问题的人。如果用一个TrackBar控制左右音道如何解决？

解决方案 »