Delphi-PRAXiS - Einzelnen Beitrag anzeigen - Delphi Zugriffsverletzung

**smepal**

Also ich bin gerade dabei einen MP3 Player zu programmieren. Dabei hat auch zunächst alles funktioniert, solange ich meine Playlist im selben Formular hatte, wie den Mediaplayer. Jetzt habe ich für die Playlist ein eigenes Formular erstellt und auch die Pfade geändert. Allerdings bekomme ich jetzt Zugriffsverletzungsmeldungen beim Klicken auf die Mediaplayer Buttons.

Hier der Code:

Die Unit des Hauptformulars:

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Delphi-Quellcode:

			unit maplayer;

interface

uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, ComCtrls, ShellCtrls, Grids, ValEdit, StdCtrls, Buttons, mmsystem,

  MPlayer, ExtCtrls, Gauges;

//Tabelle für die Playlist mit Titel, Länge und Speicherort des Tracks

type

  Tplaylist = record

    title: string;

    length: integer;

    datei: string;

end;

  TForm1 = class(TForm)

    openmp3: TOpenDialog;

    MediaPlayer1: TMediaPlayer;

    Timer1: TTimer;

    SpeedButton1: TSpeedButton;

    Bevel1: TBevel;

    Title: TLabel;

    Length: TLabel;

    Left: TLabel;

    Timer2: TTimer;

    position: TProgressBar;

    Pause: TSpeedButton;

    m3uopen: TOpenDialog;

    SpeedButton2: TSpeedButton;

    SpeedButton3: TSpeedButton;

    SpeedButton4: TSpeedButton;

    procedure FormShow(Sender: TObject);

    procedure SpeedButton4Click(Sender: TObject);

    procedure SpeedButton3Click(Sender: TObject);

    procedure SpeedButton2Click(Sender: TObject);

    procedure PauseClick(Sender: TObject);

    procedure positionMouseDown(Sender: TObject; Button: TMouseButton;

      Shift: TShiftState; X, Y: Integer);

    procedure Timer2Timer(Sender: TObject);

    procedure SpeedButton1Click(Sender: TObject);

    procedure Timer1Timer(Sender: TObject);

  private

    { Private-Deklarationen }

  public

    { Public-Deklarationen }

  end;

var

  Form1: TForm1;

  pos, noft, tpassd: Integer; //Trackposition, Azahl der Tracks, Vergangene Zeit des Aktuellen Tracks

  list: array of Tplaylist; //deklarieren der oben vereinbarten Tabelle für die Playlist

  //list hat immer den gleichen Index wie die Listbox playlist

  m3u: TStringlist;

  implementation

uses suchen, pl;

{$R *.dfm}

// Der Timer1 ist für das automatische weitergehen in der Playlist bei Trackende verantwortlich

procedure TForm1.Timer1Timer(Sender: TObject);

begin

timer2.Enabled := false;

mediaplayer1.stop;

//Der nächste Track wird ausgewählt und an den Mediaplayer übergeben

//Die Infos´werden angezeigt

pos := pos + 1;

mediaplayer1.FileName := list[pos].datei;

mediaplayer1.Open;

title.Caption := list[pos].Title;

length.caption := inttostr((mediaplayer1.tracklength[pos] div 1000) div 60)+ ' : ' + inttostr((mediaplayer1.TrackLength[pos] div 1000) mod 60);

left.Caption := inttostr(mediaplayer1.tracklength[pos] div 1000);

//Die Positionsanzeige wird eingerichtet

position.Max := mediaplayer1.TrackLength[pos];

timer1.Interval := mediaplayer1.TrackLength[0];

//Start des Abspielvorgangs

tpassd := 0;

position.Position := 0;

timer1.Enabled := true;

timer2.Enabled := true;

Mediaplayer1.Play;

end;

// Bei einfachem Klicken auf Play soll der markierte Track in der Playlist abgespielt werden

procedure TForm1.SpeedButton1Click(Sender: TObject);

begin

mediaplayer1.Stop;

mediaplayer1.Close;

timer2.Enabled := false;

timer1.Enabled := false;

mediaplayer1.Open;

mediaplayer1.FileName := list[pos].datei;

length.caption := inttostr((mediaplayer1.tracklength[0] div 1000) div 60)+ ' : ' + inttostr((mediaplayer1.TrackLength[pos] div 1000) mod 60);

left.Caption := inttostr(mediaplayer1.tracklength[0] div 1000);

position.Max := mediaplayer1.TrackLength[0];

title.Caption := list[pos].Title;

timer1.Interval := mediaplayer1.TrackLength[0];

timer1.Enabled := true;

tpassd := 0;

position.Position := 0;

timer2.Enabled := true;

Mediaplayer1.Play;

end;

// Timer2 ist zum anzeigen der übriggebliebenen Zeit da, sowie zum Weiterschreiten der Positionsanzeige

procedure TForm1.Timer2Timer(Sender: TObject);

begin

tpassd := tpassd + 1;

left.Caption := inttostr ((mediaplayer1.TrackLength[pos] div 1000) - tpassd);

position.position := position.position + 1000;

end;

//Springen des Tracks an die auf der Positionsanzeige ausgewählte Stelle

procedure TForm1.positionMouseDown(Sender: TObject; Button: TMouseButton;

  Shift: TShiftState; X, Y: Integer);

begin

position.position := round((x / position.width) * mediaplayer1.TrackLength[0]);

mediaplayer1.Stop;

timer1.Enabled := false;

tpassd := position.position div 1000;

left.Caption := inttostr ((mediaplayer1.TrackLength[pos] div 1000) - tpassd);

mediaplayer1.Startpos := position.position;

timer1.Interval := mediaplayer1.TrackLength[0] - position.position;

timer1.Enabled := true;

mediaplayer1.Play;

end;

//Pausieren des Tracks

procedure TForm1.PauseClick(Sender: TObject);

begin

if timer1.Enabled then

begin

mediaplayer1.Pause;

timer1.Enabled := false;

timer2.enabled := false;

end

else

begin

mediaplayer1.Pause;

timer1.Enabled := true;

timer2.enabled := true;

end;

end;

//Zurück

procedure TForm1.SpeedButton2Click(Sender: TObject);

begin

pos := pos - 2;

//-------Timer Procedur ------------//

timer2.Enabled := false;

mediaplayer1.stop;

pos := pos + 1;

mediaplayer1.FileName := list[pos].datei;

mediaplayer1.Open;

title.Caption := list[pos].Title;

length.caption := inttostr((mediaplayer1.tracklength[pos] div 1000) div 60)+ ' : ' + inttostr((mediaplayer1.TrackLength[pos] div 1000) mod 60);

left.Caption := inttostr(mediaplayer1.tracklength[pos] div 1000);

position.Max := mediaplayer1.TrackLength[pos];

timer1.Interval := mediaplayer1.TrackLength[0];

timer1.Enabled := true;

tpassd := 0;

position.Position := 0;

timer2.Enabled := true;

Mediaplayer1.Play;

//-----------------------------------//

end;

//Vor

procedure TForm1.SpeedButton3Click(Sender: TObject);

begin

//-------Timer Procedur ------------//

timer2.Enabled := false;

mediaplayer1.stop;

pos := pos + 1;

mediaplayer1.FileName := list[pos].datei;

mediaplayer1.Open;

title.Caption := list[pos].Title;

length.caption := inttostr((mediaplayer1.tracklength[pos] div 1000) div 60)+ ' : ' + inttostr((mediaplayer1.TrackLength[pos] div 1000) mod 60);

left.Caption := inttostr(mediaplayer1.tracklength[pos] div 1000);

position.Max := mediaplayer1.TrackLength[pos];

timer1.Interval := mediaplayer1.TrackLength[0];

timer1.Enabled := true;

tpassd := 0;

position.Position := 0;

timer2.Enabled := true;

Mediaplayer1.Play;

//-----------------------------------//

end;

//Stop

procedure TForm1.SpeedButton4Click(Sender: TObject);

begin

mediaplayer1.Stop;

 pos := 0;

 tpassd := 0;

timer1.Enabled := false;

timer1.Interval := 0;

timer2.Enabled := false;

position.Position := 0;

left.Caption := '0:00';

length.Caption := '0:00';

title.Caption := '';

form3.playlist.ItemIndex := 0;

end;

//Anzeigen der Playlist

procedure TForm1.FormShow(Sender: TObject);

begin

form3.Show;

form1.Top := 0;

end;

end.

Die Unit der Playlist:

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Delphi-Quellcode:

			unit pl;

interface

uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, StdCtrls, Menus;

//Playlist-Tabelle

type

  Tplaylist = record

    title: string;

    length: integer;

    datei: string;

    end;

    //Auslesen des ID3 Tags-Tabelle

    Type

  TID3Tag = record

    ID: string[3];

    Titel: string[30];

    Artist: string[30];

    Album: string[30];

    Year: string[4];

    Comment: string[30];

    Genre: byte;

    dauer: longint; //in sekunden;

    sample: integer;

    bits: byte;

    vers: byte;

    layers: byte;

end;

type

  TForm3 = class(TForm)

    playlist: TListBox;

    Add: TButton;

    Button1: TButton;

    Button2: TButton;

    MainMenu1: TMainMenu;

    Neu1: TMenuItem;

    Play1: TMenuItem;

    Playlist1: TMenuItem;

    Lschen1: TMenuItem;

    ffnen1: TMenuItem;

    Speichern1: TMenuItem;

    Suchennach1: TMenuItem;

    Artist1: TMenuItem;

    itle1: TMenuItem;

    Album1: TMenuItem;

    procedure itle1Click(Sender: TObject);

    procedure ffnen1Click(Sender: TObject);

    procedure Lschen1Click(Sender: TObject);

    procedure Play1Click(Sender: TObject);

    procedure FormCreate(Sender: TObject);

    procedure playlistKeyDown(Sender: TObject; var Key: Word;

      Shift: TShiftState);

    procedure Button2Click(Sender: TObject);

    procedure Button1Click(Sender: TObject);

    procedure AddClick(Sender: TObject);

    procedure playlistDblClick(Sender: TObject);

  private

    { Private-Deklarationen }

  public

    { Public-Deklarationen }

  end;

const

  MPEG_BIT_RATES : array[1..3] of array[1..3] of array[0..15] of word =

  { Version 1, Layer I }

    (((0,32,64,96,128,160,192,224,256,288,320,352,384,416,448,0),

  { Version 1, Layer II }

    (0,32,48,56, 64, 80, 96,112,128,160,192,224,256,320,384,0),

  { Version 1, Layer III }

    (0,32,40,48, 56, 64, 80, 96,112,128,160,192,224,256,320,0)),

  { Version 2, Layer I }

    ((0,32,48, 56, 64, 80, 96,112,128,144,160,176,192,224,256,0),

  { Version 2, Layer II }

    (0, 8,16,24, 32, 40, 48, 56, 64, 80, 96, 112,128,144,160,0),

  { Version 2, Layer III }

    (0, 8,16,24, 32, 40, 48, 56, 64, 80, 96, 112,128,144,160,0)),

  { Version 2.5, Layer I }

    ((0,32,48, 56, 64, 80, 96,112,128,144,160,176,192,224,256,0),

  { Version 2.5, Layer II }

    (0, 8,16,24, 32, 40, 48, 56, 64, 80, 96, 112,128,144,160,0),

  { Version 2.5, Layer III }

    (0, 8,16,24, 32, 40, 48, 56, 64, 80, 96, 112,128,144,160,0)));

  sample_rates: array[1..3] of array [0..3] of word=

    ((44100,48000,32000,0),

    (22050,24000,16000,0),

    (11025,12000,8000,0));

var

  Form3: TForm3;

  pos, noft, tpassd: Integer; //Trackposition, Azahl der Tracks, Vergangene Zeit des Aktuellen Tracks

  list: array of Tplaylist; //deklarieren der oben vereinbarten Tabelle für die Playlist

  //list hat immer den gleichen Index wie die Listbox playlist

  ID3Tag: TID3Tag;

  m3u: TStringlist;

implementation

uses maplayer, suchen;

{$R *.dfm}

//-------------------------------------//

procedure Lese_ID3Tag(Filename: string);

var

  Buffer: array[1..128] of char;

  F: File;

  mp3hdrread: array[1..4] of byte;

  mp3hdr: longint absolute mp3hdrread;

  tempbyte, bitrateindex, versionindex: byte;

  bitrate, version, layer, groese: longint;

begin

  AssignFile(F, Filename);

  Reset(F,1);

  groese:=filesize(f);

  blockread(f,mp3hdrread,4);

  tempbyte:=mp3hdrread[1];

  mp3hdrread[1]:=mp3hdrread[4];

  mp3hdrread[4]:=tempbyte;

  tempbyte:=mp3hdrread[2];

  mp3hdrread[2]:=mp3hdrread[3];

  mp3hdrread[3]:=tempbyte;

  reset(f,1);

  Seek(F,FileSize(F)-128);

  BlockRead(F, Buffer, SizeOf(Buffer));

  CloseFile(F);

  bitrateindex:=((mp3hdr shr 12) and $F);

  versionindex:=((mp3hdr shr 19) and $3);

  case versionindex of

    0: version:=3;

    1: version:=0; //unbekannt

    2: version:=2;

    3: version:=1;

  end;

  layer:=4-((mp3hdr shr 17) and $3);

  if version<>0 then

    bitrate:=MPEG_BIT_RATES[version][layer][bitrateindex]

  else

    bitrate:=128;

  with ID3Tag do

  begin

    ID:=copy(Buffer,1,3);

    Titel:=copy(Buffer,4,30);

    Artist:=copy(Buffer,34,30);

    Album:=copy(Buffer,64,30);

    Year:=copy(Buffer,94,4);

    Comment:=copy(Buffer,98,30);

    Genre:=ord(Buffer[128]);

    sample:=sample_rates[version][((mp3hdr shr 10) and $3)];

    dauer:=(groese*8) div ((bitrate)*1000);

    bits:=bitrate;

    vers:=version;

    layers:=layer;

  end;

end;

//------------------------------------------------//

// Zum Abspielen des doppelt angeklickten Tracks // Funktioniert //

procedure TForm3.playlistDblClick(Sender: TObject);

begin

form1.timer2.Enabled := false;

form1.title.Caption := list[playlist.itemindex].Title;

form1.mediaplayer1.FileName := list[playlist.itemindex].datei;

pos := playlist.ItemIndex;

form1.mediaplayer1.Open;

form1.timer1.Interval := form1.mediaplayer1.TrackLength[0];

form1.timer1.Enabled := true;

tpassd := 0;

form1.left.Caption := inttostr(form1.mediaplayer1.tracklength[pos] div 1000);

form1.position.Max := form1.mediaplayer1.TrackLength[0];

form1.position.Position := 0;

form1.timer2.Enabled := true;

form1.Mediaplayer1.Play;

form1.length.caption := inttostr((form1.mediaplayer1.tracklength[pos] div 1000) div 60)+ ' : ' + inttostr((form1.mediaplayer1.TrackLength[pos] div 1000) mod 60);

end;

//______Hinzufügen von einzelnen MP3´s________//

procedure TForm3.AddClick(Sender: TObject);

var i: Integer;

datei: String;

begin

if form1.openmp3.Execute then

begin

SetLength(list, 100000);

for i := 0 to form1.openmp3.Files.Count - 1 do

begin

datei := form1.openmp3.Files[i];

Lese_ID3Tag(datei);

list[i+noft].title := ID3Tag.Titel;

list[i+noft].length := ID3Tag.dauer;

list[i+noft].datei := datei;

if not (list[i+noft].title = '') then

playlist.Items.add (list[i+noft].title)

else

playlist.Items.add(form1.openmp3.filename);

end;

end;

noft := playlist.items.count;

end;

//Laden einer m3u Playlist

procedure TForm3.Button1Click(Sender: TObject);

var i,e, position: Integer;

datei : String;

begin

playlist.Clear;

noft := 0;

SetLength(list, 100000);

m3u := TStringlist.Create;

  if form1.m3uopen.Execute then

  begin

    m3u.LoadFromFile(form1.m3uopen.filename);

    if m3u.Strings[0] = '#EXTM3U' then

      begin

      e := 0;

      for i := 0 to m3u.Count - 1 do

        begin

        position := ansipos ('#' , m3u.Strings[i]);

        if not (position = 1) then

          begin

            try

            datei := m3u.Strings[i];

            Lese_ID3Tag(datei);

            list[e].title := ID3Tag.Titel;

            list[e].length := ID3Tag.dauer;

            list[e].datei := datei;

            playlist.Items.add (list[e].title);

            except

             datei := m3u.Strings[e];

             playlist.Items.add (datei);

            end;

            e := e+1;

          end;

        end;

      noft := playlist.items.count;

      form3.Caption := form1.m3uopen.FileName;

      end

    else

    showmessage ('Keine gültige m3u-Playlist!');

  end;

end;

//Aufrufen der Suchfunktion

procedure TForm3.Button2Click(Sender: TObject);

begin

form2.showmodal;

end;

procedure TForm3.playlistKeyDown(Sender: TObject; var Key: Word;

  Shift: TShiftState);

begin

if (Key = ord('S') ) then

form2.showmodal;

end;

procedure TForm3.FormCreate(Sender: TObject);

begin

form3.Left := 0;

form3.Top := form1.Top + form1.Height + 10;

end;

procedure TForm3.Play1Click(Sender: TObject);

begin

add.Click;

end;

procedure TForm3.Lschen1Click(Sender: TObject);

begin

playlist.Clear;

pos := 0;

noft := 0;

end;

procedure TForm3.ffnen1Click(Sender: TObject);

begin

button1.Click;

end;

procedure TForm3.itle1Click(Sender: TObject);

begin

form2.ShowModal;

end;

end.

Die Unit fürs Tracksuchen:
(Funktioniert einwandfrei!)

zusammenfalten · markieren

Delphi-Quellcode:

			unit suchen;

interface

uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, StdCtrls;

type

  TForm2 = class(TForm)

    search: TEdit;

    result: TListBox;

    procedure resultDblClick(Sender: TObject);

    procedure searchChange(Sender: TObject);

  private

    { Private-Deklarationen }

  public

    { Public-Deklarationen }

  end;

var

  Form2: TForm2;

implementation

uses maplayer, pl;

{$R *.dfm}

procedure TForm2.searchChange(Sender: TObject);

var no, i, pos: Integer;

begin

result.clear;

no := form3.playlist.items.count;

for i := 0 to no - 1 do

begin

pos := ansipos(search.Text, form3.playlist.items[i]);

if pos > 0 then

result.Items.add(form3.playlist.Items[i]);

end;

end;

procedure TForm2.resultDblClick(Sender: TObject);

var i: Integer;

begin

for i := 0 to form3.playlist.Count - 1 do

begin

if form3.playlist.Items[i] = result.Items[result.itemindex] then

form3.playlist.ItemIndex := i;

end;

form2.close;

end;

end.

So und hier noch mal alles zum Runterladen:

Einzelnen Beitrag anzeigen

Zugriffsverletzung - Audioplayer