Use multi-media library bass. DLL to play MP3 [4]-display and set the playback progress

// Obtain the length of the file stream, in the unit of byte function bass_channelgetlength (handle: DWORD; {stream handle} mode: DWORD {acquisition mode; there are two options, however, hstream can only use bass_pos_byte}): qword; stdcall; External bassdll; // gets the current pointer position of the stream, in the unit of byte function bass_channelgetposition (handle: DWORD; {stream handle} mode: DWORD {retrieval mode; two options are available, but the hstream can only use bass_pos_byte}): qword; stdcall; External bassdll; // obtain the time point based on the stream pointer position, in seconds. It is a very precise floating point function bass_channelbytes2seconds (handle: DWORD; {stream handle} pos: qword {stream pointer position, in bytes, qword = int64}): Double; stdcall; External bassdll; // opposite to bass_channelbytes2seconds, bass_channelseconds2bytes can obtain the stream pointer position through time. function bass_channelseconds2bytes (handle: DWORD; pos: Double): qword; stdcall; External bassdll; // opposite to bass_channelgetposition, bass_channelsetposition can be used to set the stream pointer position. function bass_channelsetposition (handle: DWORD; pos: qword; Mode: DWORD): bool; stdcall; External bassdll;
  
   
 
// The total time for obtaining music can be: bass_channelbytes2seconds (HS, bass_channelgetlength (HS, bass_pos_byte); // The current time for obtaining music playback can be: Upper (HS, bass_channelgetposition (HS, HS, bass_pos_byte ));
  
   
 

In this example:

Code File:

Unit unit1; interfaceuses windows, messages, sysutils, variants, classes, graphics, controls, forms, dialogs, classes, extctrls; Type tform1 = Class (tform) opendialog1: topendialog; timer1: ttimer; button1: tbutton; button2: tbutton; button3: tbutton; weight: weight; Procedure handle (Sender: tobject); Procedure button2click (Sender: tobject); proce Dure button3click (Sender: tobject); Procedure handle (Sender: tobject; scrollcode: tscrollcode; var scrollpos: integer); Procedure formdestroy (Sender: tobject); end; var form1: tform1; implementation {$ R *. DFM} uses bass; var HS: hstream; {stream handle} Time: Double; {total music time} procedure tform1.formcreate (Sender: tobject); begin timer1.interval: = 100; timer1.enabled: = False; scrollbar1.enabled: = false; If hiword (bass_getversion) bassversion then MessageBox (0, '"Bass. dll" file version is not suitable! ', Nil, mb_iconerror); if not bass_init (-1, 44100, 0, 0, nil) Then showmessage ('initialization error'); end; {open} procedure tform1.button1click (Sender: tobject); var mp3path: ansistring; begin bass_streamfree (HS); timer1.enabled: = false; scrollbar1.enabled: = false; opendigalo1.filter: = 'mp3 file (*. MP3) | *. MP3 | WAV file (*. wav) | * WAV '; If opendialog1.execute then mp3path: = ansistring (opendialog1.filename); HS: = bass_streamcreatefile (false, pansichar (mp3path), 0, 0, 0); if hs

Form file:

Object form1: tform1 left = 205 Top = 107 caption = 'form1' clientheight = 88 clientwidth = 393 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 = 65 Top = 17 width = 75 Height = 25 caption = #25171 #24320 taborder = 0 onclick = button1click end object button2: tbutton left = 161 Top = 17 width = 75 Height = 25 caption = #25773 #25918 taborder = 1 onclick = button2click end object button3: tbutton left = 257 Top = 17 width = 75 Height = 25 caption = #26242 #20572 taborder = 2 onclick = button3click end object scrollbar1: tscrollbar left = 8 Top = 56 width = 377 Height = 17 pagesize = 0 taborder = 3 onscroll = scrollbar1scroll end object opendialog1: topendialog left = 40 top = 40 end object timer1: ttimer ontimer = timer1timer left = 80 top = 48 endend