用多媒体库 Bass.dll 播放 mp3 : 如何从内存流播放

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;

type
TForm1 = class(TForm)
OpenDialog1: TOpenDialog;
Button1: TButton;
Button2: TButton;
Button3: TButton;
Button4: TButton;
procedure FormCreate(Sender: TObject);
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure Button3Click(Sender: TObject);
procedure Button4Click(Sender: TObject);
procedure FormDestroy(Sender: TObject);
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

uses Bass;

var
hs: HSTREAM;
mem: TMemoryStream; {新加的}

procedure TForm1.FormCreate(Sender: TObject);
begin
if HiWord(BASS_GetVersion) <> BASSVERSION then
MessageBox(0, '"Bass.dll" 文件版本不合适! ', nil, MB_ICONERROR);

if not BASS_Init(-1, 44100, 0, 0, nil) then
ShowMessage('初始化错误');
end;

procedure TForm1.Button1Click(Sender: TObject);
var
Mp3Path: string;
begin
OpenDialog1.Filter := 'Mp3 文件(*.mp3)|*.mp3|Wav 文件(*.wav)|*wav';
if OpenDialog1.Execute then Mp3Path := OpenDialog1.FileName;

{下面几行是与原来不同的代码}
if not Assigned(mem) then mem := TMemoryStream.Create;
mem.LoadFromFile(Mp3Path);
mem.Position := 0;

BASS_StreamFree(hs);
hs := BASS_StreamCreateFile(True, mem.Memory, 0, mem.Size, 0);

if hs < BASS_ERROR_ENDED then
Text := '打开失败' else Text := string(Mp3Path);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
BASS_ChannelPlay(hs, False);
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
BASS_ChannelPause(hs);
end;

procedure TForm1.Button4Click(Sender: TObject);
begin
BASS_ChannelStop(hs);
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
BASS_Free;
if Assigned(mem) then mem.Free; {这也是新加的}
end;

end.