IDirectSoundBuffer.GetStatus() 用于获取缓冲区的当前状态, 譬如是否正在播放、是否指定为循环播放等等.
IDirectSound8.DuplicateSoundBuffer() 是通过根据已存在的缓冲区建立缓冲区副本, 这类似引用; 通过它可以让同一个声音交叉播放.
复制缓冲区不能复制主缓冲区.
示例:
unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls; type TForm1 = class(TForm) Button1: TButton; //播放 buf Button2: TButton; //播放 bufs[0] Button3: TButton; //播放 bufs[1] Button4: TButton; //全部停止 CheckBox1: TCheckBox; //控制是否循环播放 procedure FormCreate(Sender: TObject); procedure FormDestroy(Sender: TObject); procedure Button1Click(Sender: TObject); procedure Button3Click(Sender: TObject); procedure Button2Click(Sender: TObject); procedure Button4Click(Sender: TObject); procedure CheckBox1Click(Sender: TObject); end; var Form1: TForm1; implementation {$R *.dfm} uses DirectSound, MMSystem, ReadWave; //ReadWave 是前面(7)自定义的单元 var myDSound: IDirectSound8; buf: IDirectSoundBuffer; //准备用这个缓冲区载入波形 bufs: array[0..1] of IDirectSoundBuffer; //这个缓冲区数组都将复制上面的 buf loop: DWORD = 0; //是否循环播放; 0:不循环; 1(DSBPLAY_LOOPING):循环 {判断缓冲区是否正在播放的函数} function IsPlay(b: IDirectSoundBuffer): Boolean; var dStatus: DWORD; begin Result := b <> nil; if Succeeded(b.GetStatus(dStatus)) then Result := dStatus and DSBSTATUS_PLAYING = DSBSTATUS_PLAYING; end; {初始化设备} procedure TForm1.FormCreate(Sender: TObject); var wavFormat: TWaveFormatEx; bufDesc: TDSBufferDesc; wavPath: string; wav: TReadWave; p1: Pointer; n1: DWORD; i: Integer; begin with TOpenDialog.Create(nil) do begin Filter := 'Wave File(*.wav)|*.wav'; if Execute then wavPath := FileName; Free; end; wav := TReadWave.Create; if not wav.Open(wavPath) then begin ShowMessage('打开失败'); wav.Free; Application.Terminate; end; DirectSoundCreate8(nil, myDSound, nil); myDSound.SetCooperativeLevel(Handle, DSSCL_NORMAL); ZeroMemory(@bufDesc, SizeOf(TDSBufferDesc)); bufDesc.dwSize := SizeOf(TDSBufferDesc); bufDesc.dwFlags := DSBCAPS_STATIC; bufDesc.dwBufferBytes := wav.Size; bufDesc.lpwfxFormat := @wav.Format; {建立 buf 并载入波形} myDSound.CreateSoundBuffer(bufDesc, buf, nil); buf.Lock(0, 0, @p1, @n1, nil, nil, DSBLOCK_ENTIREBUFFER); wav.Read(p1, n1); wav.Free; buf.Unlock(p1, n1, nil, 0); {根据 buf 复制几个缓冲区} for i := Low(bufs) to High(bufs) do begin myDSound.DuplicateSoundBuffer(buf, bufs[i]); end; end; {播放或暂停 buf} procedure TForm1.Button1Click(Sender: TObject); begin if IsPlay(buf) then buf.Stop else buf.Play(0, 0, loop); end; {播放或暂停 buf[0]} procedure TForm1.Button2Click(Sender: TObject); begin if IsPlay(bufs[0]) then buf.Stop else bufs[0].Play(0, 0, loop); end; {播放或暂停 buf[1]} procedure TForm1.Button3Click(Sender: TObject); begin if IsPlay(bufs[1]) then buf.Stop else bufs[1].Play(0, 0, loop); end; {全部停止} procedure TForm1.Button4Click(Sender: TObject); var i: Integer; begin if buf <> nil then buf.Stop; for i := Low(bufs) to High(bufs) do if bufs[i] <> nil then bufs[i].Stop; end; {切换是否循环播放, 没有对正在播放的缓冲区进行控制} procedure TForm1.CheckBox1Click(Sender: TObject); begin loop := DWORD(CheckBox1.Checked); end; procedure TForm1.FormDestroy(Sender: TObject); var i: Integer; begin buf := nil; for i := Low(bufs) to High(bufs) do bufs[i] := nil; myDSound := nil; end; end.