用多媒體庫 Bass.dll 播放 mp3 [3] – 開啟、播放、暫停、停止

//播放前先要用 BASS_Init 函數進行播放裝置初始化function BASS_Init(  device: Integer; {指定輸出裝置, 第一個是 1、第二個是 2; -1 表示使用當前裝置}  freq: DWORD;     {採樣率, 一般是 44100}  flags: DWORD;    {是 BASS_DEVICE_MONO 等常量的組合值, 是效果參數; 0 是預設值}  win: HWND;       {指定視窗控制代碼; 0 表示當前視窗}  clsid: PGUID     {指定一個 GUID, 用以初始化 DirectSound; nil 表示使用預設}): BOOL; stdcall; external bassdll;//當然需要從檔案或記憶體負載檔案流以後才能播放function BASS_StreamCreateFile(  mem: BOOL;     {從檔案載入這裡是 False; 從記憶體載入這裡是 True}  f: Pointer;    {檔案名稱或記憶體流的指標}  offset: QWORD; {播放起始點, 單位是 1/10 毫秒; 只在參數 1: mem = False 時有效; 預設是 0}  length: QWORD; {播放終止點, 單位是 1/10 毫秒; 只在參數 1: mem = False 時有效; 預設是 0}  flags: DWORD   {BASS_SAMPLE_3D 等參數的組合; 控制播放效果、反覆和解碼等等}): HSTREAM; stdcall; external bassdll;{另外: 在調入記憶體流時, 參數 length 要指定為流的大小}

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代碼檔案:

unit Unit1;interfaceuses  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; {流控制代碼}procedure TForm1.FormCreate(Sender: TObject);begin  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 mp3 檔案, 並建立播放流}procedure TForm1.Button1Click(Sender: TObject);var  Mp3Path: AnsiString;begin  {開啟檔案}  OpenDialog1.Filter := 'Mp3 檔案(*.mp3)|*.mp3|Wav 檔案(*.wav)|*wav';  if OpenDialog1.Execute then    Mp3Path := AnsiString(OpenDialog1.FileName);  {如果已有檔案開啟, 先要釋放它}  BASS_StreamFree(hs);  {建立播放流}  hs := BASS_StreamCreateFile(False, PAnsiChar(Mp3Path), 0, 0, 0);  {是否開啟成功, 顯示一下}  if hs 

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object Form1: TForm1  Left = 0  Top = 0  Caption = 'Form1'  ClientHeight = 117  ClientWidth = 202  Color = clBtnFace  Font.Charset = DEFAULT_CHARSET  Font.Color = clWindowText  Font.Height = -11  Font.Name = 'Tahoma'  Font.Style = []  OldCreateOrder = False  OnCreate = FormCreate  OnDestroy = FormDestroy  PixelsPerInch = 96  TextHeight = 13  object Button1: TButton    Left = 16    Top = 17    Width = 75    Height = 25    Caption = #25171#24320    TabOrder = 0    OnClick = Button1Click  end  object Button2: TButton    Left = 112    Top = 17    Width = 75    Height = 25    Caption = #25773#25918    TabOrder = 1    OnClick = Button2Click  end  object Button3: TButton    Left = 112    Top = 48    Width = 75    Height = 25    Caption = #26242#20572    TabOrder = 2    OnClick = Button3Click  end  object Button4: TButton    Left = 112    Top = 79    Width = 75    Height = 25    Caption = #20572#27490    TabOrder = 3    OnClick = Button4Click  end  object OpenDialog1: TOpenDialog    Left = 40    Top = 56  endend