用多媒體庫 Bass.dll 播放 mp3 [11] – 使用回呼函數設定反覆

本例:

代碼檔案:

unit Unit1;interfaceuses  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,  Dialogs, StdCtrls, ExtCtrls, ComCtrls, Bass;type  TForm1 = class(TForm)    OpenDialog1: TOpenDialog;    Timer1: TTimer;    PaintBox1: TPaintBox;    Button1: TButton;    Button2: TButton;    Button3: TButton;    Button4: TButton;    Button5: TButton;    Shape1: TShape;    Shape2: TShape;    Shape3: TShape;    Label1: TLabel;    procedure FormCreate(Sender: TObject);    procedure Button1Click(Sender: TObject);    procedure Button2Click(Sender: TObject);    procedure Button3Click(Sender: TObject);    procedure FormDestroy(Sender: TObject);    procedure PaintBox1Paint(Sender: TObject);    procedure Timer1Timer(Sender: TObject);    procedure PaintBox1MouseDown(Sender: TObject; Button: TMouseButton;      Shift: TShiftState; X, Y: Integer);    procedure Button4Click(Sender: TObject);    procedure Button5Click(Sender: TObject);  private    procedure Draw;  end;  procedure MySyncLoop(handle: HSYNC; channel, data, user: DWORD); stdcall;var  Form1: TForm1;implementation{$R *.dfm}//uses Bass;var  hs: HSTREAM;  {流控制代碼}  Data: array of Cardinal;  bit: TBitmap;  hSyncLoop: Cardinal; {回呼函數控制代碼}  Mp3Len: Cardinal;    {Mp3 總的位元組長度}procedure TForm1.FormCreate(Sender: TObject);begin  Label1.Caption := '提示: 滑鼠左鍵設定反覆起始點(黃線); 右鍵設定反覆拐點(紅線).';  Timer1.Enabled := False;  Timer1.Interval := 100;  Shape1.Pen.Style := psClear;  Shape1.Brush.Color := clWhite;  Shape1.Width := 3;  Shape1.Height := PaintBox1.Height;  Shape1.Top := 0;  Shape1.Left := -1;  Shape2.Pen.Style := psClear;  Shape2.Brush.Color := clYellow;  Shape2.Width := 3;  Shape2.Height := PaintBox1.Height;  Shape2.Top := 0;  Shape2.Visible := False;  Shape3.Pen.Style := psClear;  Shape3.Brush.Color := clRed;  Shape3.Width := 3;  Shape3.Height := PaintBox1.Height;  Shape3.Top := 0;  Shape3.Visible := False;  bit := TBitmap.Create;  PaintBox1.Align := alTop;  if HiWord(BASS_GetVersion)  BASSVERSION then    MessageBox(0, '"Bass.dll" 檔案版本不合適! ', nil, MB_ICONERROR);  if not BASS_Init(-1, 44100, 0, 0, nil) then ShowMessage('初始化錯誤');end;{開啟}procedure TForm1.Button1Click(Sender: TObject);var  Mp3Path: AnsiString;  i: Cardinal;  time: Double;  hs2: HSTREAM;begin  BASS_StreamFree(hs);  OpenDialog1.Filter := 'Mp3 檔案(*.mp3)|*.mp3|Wav 檔案(*.wav)|*wav';  if OpenDialog1.Execute then    Mp3Path := AnsiString(OpenDialog1.FileName);  hs := BASS_StreamCreateFile(False, PAnsiChar(Mp3Path), 0, 0, 0);  if hs 

表單檔案:

object Form1: TForm1  Left = 222  Top = 114  Caption = 'Form1'  ClientHeight = 177  ClientWidth = 476  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 PaintBox1: TPaintBox    Left = 16    Top = 0    Width = 105    Height = 105    OnMouseDown = PaintBox1MouseDown    OnPaint = PaintBox1Paint  end  object Shape1: TShape    Left = 170    Top = 24    Width = 65    Height = 65  end  object Shape2: TShape    Left = 241    Top = 24    Width = 65    Height = 65  end  object Shape3: TShape    Left = 312    Top = 24    Width = 65    Height = 65  end  object Label1: TLabel    Left = 11    Top = 156    Width = 31    Height = 13    Caption = 'Label1'  end  object Button1: TButton    Left = 8    Top = 120    Width = 75    Height = 25    Caption = #25171#24320    TabOrder = 0    OnClick = Button1Click  end  object Button2: TButton    Left = 89    Top = 120    Width = 75    Height = 25    Caption = #25773#25918    TabOrder = 1    OnClick = Button2Click  end  object Button3: TButton    Left = 170    Top = 120    Width = 75    Height = 25    Caption = #26242#20572    TabOrder = 2    OnClick = Button3Click  end  object Button4: TButton    Left = 251    Top = 120    Width = 75    Height = 25    Caption = #20174#22836#25773#25918    TabOrder = 3    OnClick = Button4Click  end  object Button5: TButton    Left = 375    Top = 120    Width = 93    Height = 25    Caption = #28165#38500#21453#22797#26631#35760    TabOrder = 4    OnClick = Button5Click  end  object OpenDialog1: TOpenDialog    Left = 128    Top = 24  end  object Timer1: TTimer    OnTimer = Timer1Timer    Left = 128    Top = 72  endend