本例效果图:
代码文件:
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, ComCtrls;
type
TForm1 = class(TForm)
OpenDialog1: TOpenDialog;
Button1: TButton;
Button2: TButton;
Button3: TButton;
TrackBar1: TTrackBar;
Label1: TLabel;
Button4: TButton;
procedure FormCreate(Sender: TObject);
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure Button3Click(Sender: TObject);
procedure TrackBar1Change(Sender: TObject);
procedure FormDestroy(Sender: TObject);
procedure Button4Click(Sender: TObject);
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
uses Bass;
var
hs: HSTREAM; {流句柄}
procedure TForm1.FormCreate(Sender: TObject);
begin
TrackBar1.ShowSelRange := False;
TrackBar1.Height := 23;
TrackBar1.Max := 100000;
TrackBar1.Min := 100;
TrackBar1.Position := 44100;
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;
{打开}
procedure TForm1.Button1Click(Sender: TObject);
var
Mp3Path: AnsiString;
begin
BASS_StreamFree(hs);
OpenDialog1.Filter := 'Mp3 文件(*.mp3)|*.mp3|Wav 文件(*.wav)|*wav';
if OpenDialog1.Execute then
Mp3Path := AnsiString(OpenDialog1.FileName);
hs := BASS_StreamCreateFile(False, PAnsiChar(Mp3Path), 0, 0, 0);
if hs < BASS_ERROR_ENDED then
Text := '打开失败'
else begin
Text := string(Mp3Path);
Button4.Click;
end;
end;
{播放}
procedure TForm1.Button2Click(Sender: TObject);
begin
BASS_ChannelPlay(hs, False);
end;
{暂停}
procedure TForm1.Button3Click(Sender: TObject);
begin
BASS_ChannelPause(hs);
end;
{原速}
procedure TForm1.Button4Click(Sender: TObject);
begin
TrackBar1.Position := 44100;
end;
{设置和获取播放速度}
procedure TForm1.TrackBar1Change(Sender: TObject);
var
freq: Single;
begin
freq := 44100;
BASS_ChannelSlideAttribute(hs, BASS_ATTRIB_FREQ, TrackBar1.Position, 0);
BASS_ChannelGetAttribute(hs, BASS_ATTRIB_FREQ, freq);
Label1.Caption := Format('当前速度比例: %f%%', [freq/44100]);
end;
procedure TForm1.FormDestroy(Sender: TObject);
begin
BASS_Free;
end;
end.