本例效果圖:
代碼文件:
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, ExtCtrls, ComCtrls;
type
TForm1 = class(TForm)
OpenDialog1: TOpenDialog;
TrackBar1: TTrackBar;
Timer1: TTimer;
Button1: TButton;
Button2: TButton;
Button3: TButton;
procedure FormCreate(Sender: TObject);
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure Button3Click(Sender: TObject);
procedure FormDestroy(Sender: TObject);
procedure Timer1Timer(Sender: TObject);
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
uses Bass;
var
hs: HSTREAM; {流句柄}
{回調函數: MySync1; 盡管沒有用到其中的任何參數, 但也要按指定的參數格式來寫}
procedure MySync1(handle: HSYNC; channel, data, user: DWORD); stdcall;
begin
Form1.Text := '開始播放了';
end;
{回調函數: MySync2}
{參數1: 是回調句柄, 它可有 BASS_ChannelSetSync 返回, 並可用 BASS_ChannelRemoveSync 刪除}
{參數2: 流句柄}
{參數3: 不知道}
{參數4: 是 BASS_ChannelSetSync 指定的用戶數據}
procedure MySync2(handle: HSYNC; channel, data, user: DWORD); stdcall;
begin
Form1.Text := '已過中點';
{假如播放到此(中間點)就從頭反復, 可以這樣:}
//BASS_ChannelPlay(channel, True);
end;
{回調函數: MySync3; 盡管沒有用到其中的任何參數, 但也必須按要求指定}
procedure MySync3(handle: HSYNC; channel, data, user: DWORD); stdcall;
begin
Form1.Text := '播放完畢';
end;
{初始化}
procedure TForm1.FormCreate(Sender: TObject);
begin
TrackBar1.Height := 23;
Timer1.Enabled := False;
Timer1.Interval := 100;
if HiWord(BASS_GetVersion) <> BASSVERSION then
MessageBox(0, '"Bass.dll" 文件版本不合適! ', nil, MB_ICONERROR);
if not BASS_Init(-1, 44100, 0, 0, nil) then ShowMessage('初始化錯誤');
end;
{打開}
procedure TForm1.Button1Click(Sender: TObject);
var
Mp3Path: AnsiString;
Mp3Len: Cardinal;
begin
BASS_StreamFree(hs);
Timer1.Enabled := False;
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 := '打開失敗'
else begin
Text := string(Mp3Path);
{先獲取流的字節總長度, 下面有用}
Mp3Len := BASS_ChannelGetLength(hs, BASS_POS_BYTE);
TrackBar1.Max := Mp3Len;
{開始播放是回調 MySync1}
{參數1: 流句柄; 參數2: 參數類型; 參數3: 參數值; 參數4: 要回調函數指針; 參 數5: 用戶數據}
BASS_ChannelSetSync(hs, BASS_SYNC_POS, 0, @MySync1, nil);
{播放到中間時回調 MySync2}
BASS_ChannelSetSync(hs, BASS_SYNC_POS, Mp3Len div 2, @MySync2, nil);
{播放結束時回調 MySync3}
BASS_ChannelSetSync(hs, BASS_SYNC_END, 0, @MySync3, nil);
{當然也可以寫做:}
//BASS_ChannelSetSync(hs, BASS_SYNC_POS, Mp3Len, @MySync3, nil);
{如果第二個參數同時指定 BASS_SYNC_ONETIME, 回調函數將只執行一次}
BASS_ChannelSetSync(hs, BASS_SYNC_END or BASS_SYNC_ONETIME, 0, @MySync3, nil);
end;
end;
{播放}
procedure TForm1.Button2Click(Sender: TObject);
begin
BASS_ChannelPlay(hs, False);
Timer1.Enabled := True;
end;
{暫停}
procedure TForm1.Button3Click(Sender: TObject);
begin
BASS_ChannelPause(hs);
Timer1.Enabled := False;
end;
procedure TForm1.FormDestroy(Sender: TObject);
begin
BASS_Free;
end;
procedure TForm1.Timer1Timer(Sender: TObject);
begin
if BASS_ChannelIsActive(hs) = BASS_ACTIVE_PLAYING then
TrackBar1.Position := BASS_ChannelGetPosition(hs, BASS_POS_BYTE);
end;
end.
窗體文件:
object Form1: TForm1
Left = 222
Top = 114
Caption = 'Form1'
ClientHeight = 84
ClientWidth = 254
Color = clBtnFace
Font.Charset = DEFAULT_CHARSET
Font.Color = clWindowText
Font.Height = -11
Font.Name = 'Tahoma'
Font.Style = []
OldCreateOrder = False
Position = poDesigned
OnCreate = FormCreate
OnDestroy = FormDestroy
PixelsPerInch = 96
TextHeight = 13
object Button1: TButton
Left = 8
Top = 18
Width = 75
Height = 25
Caption = #25171#24320
TabOrder = 0
OnClick = Button1Click
end
object Button2: TButton
Left = 89
Top = 18
Width = 75
Height = 25
Caption = #25773#25918
TabOrder = 1
OnClick = Button2Click
end
object Button3: TButton
Left = 170
Top = 18
Width = 75
Height = 25
Caption = #26242#20572
TabOrder = 2
OnClick = Button3Click
end
object TrackBar1: TTrackBar
Left = 1
Top = 53
Width = 250
Height = 28
TabOrder = 3
end
object OpenDialog1: TOpenDialog
Left = 72
Top = 32
end
object Timer1: TTimer
OnTimer = Timer1Timer
Left = 152
Top = 32
end
