用多媒體庫 Bass.dll 播放 mp3 [9] – 繪製波形圖

本例:

代碼檔案:

unit Unit1;interfaceuses  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,  Dialogs, StdCtrls, ExtCtrls, ComCtrls;type  TForm1 = class(TForm)    OpenDialog1: TOpenDialog;    PaintBox1: TPaintBox;    Button1: TButton;    Button2: TButton;    Button3: TButton;    ColorBox1: TColorBox;    ColorBox2: TColorBox;    procedure FormCreate(Sender: TObject);    procedure Button1Click(Sender: TObject);    procedure Button2Click(Sender: TObject);    procedure Button3Click(Sender: TObject);    procedure ColorBox1Change(Sender: TObject);    procedure ColorBox2Change(Sender: TObject);    procedure FormDestroy(Sender: TObject);    procedure PaintBox1Paint(Sender: TObject);  private    procedure Draw;  end;var  Form1: TForm1;implementation{$R *.dfm}uses Bass;var  hs: HSTREAM;  {流控制代碼}  Data: array of Cardinal;  bit: TBitmap;procedure TForm1.FormCreate(Sender: TObject);begin  bit := TBitmap.Create;  PaintBox1.Align := alTop;  ColorBox1.Selected := clBlack;  ColorBox2.Selected := clLime;  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 = 173  ClientWidth = 504  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 = 40    Top = 0    Width = 105    Height = 131    OnPaint = PaintBox1Paint  end  object Button1: TButton    Left = 8    Top = 137    Width = 75    Height = 25    Caption = #25171#24320    TabOrder = 0    OnClick = Button1Click  end  object Button2: TButton    Left = 89    Top = 137    Width = 75    Height = 25    Caption = #25773#25918    TabOrder = 1    OnClick = Button2Click  end  object Button3: TButton    Left = 170    Top = 137    Width = 75    Height = 25    Caption = #26242#20572    TabOrder = 2    OnClick = Button3Click  end  object ColorBox1: TColorBox    Left = 315    Top = 139    Width = 85    Height = 22    ItemHeight = 16    TabOrder = 3    OnChange = ColorBox1Change  end  object ColorBox2: TColorBox    Left = 406    Top = 139    Width = 90    Height = 22    ItemHeight = 16    TabOrder = 4    OnChange = ColorBox2Change  end  object OpenDialog1: TOpenDialog    Left = 192    Top = 32  endend