Delphi dicas

Arquivos avi e wav em tabelas paradox

{O exemplo abaixo demonstra como gravar um arquivo .AVI ou .WAV dentro de um arquivo paradox. Mostra também como reproduzir estes arquivos.



Para que o código abaixo funcione inclua em um Form 02 componentes Button, 01 componente Panel, 01 componente DBGrid, 01 componente Table, 01 componente DataSource e 01 componente OpenDialog.



Crie um arquivo Paradox com a seguinte estrutura:



Nome Tipo Tamanho

Codigo +

Nome A 100

Avi B

}

unit Unit1;

interface

uses

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

StdCtrls, Db, DBTables, ExtCtrls, MPlayer, DBCtrls, Grids, DBGrids;

type

        TForm1 = class(TForm)

        Button1: TButton;

        Button2: TButton;

        Table1: TTable;

        DataSource1: TDataSource;

        DBGrid1: TDBGrid;

        Panel1: TPanel;

        OpenDialog1: TOpenDialog;

        Table1Codigo: TAutoIncField;

        Table1Nome: TStringField;

        Table1Avi: TBlobField;

        procedure Button1Click(Sender: TObject);

        procedure Button2Click(Sender: TObject);

        procedure FormDestroy(Sender: TObject);

        procedure FormShow(Sender: TObject);

        procedure FormClose(Sender: TObject; var Action: TCloseAction);

        private

        { Private declarations }

        public

        { Public declarations }

end;

var Form1: TForm1;

FileName : string;

MediaPlayer1 : TMediaPlayer;



implementation

{$R *.DFM}

{Esta função cria um arquivo temporário para o sistema}

function GetTemporaryFileName : string;

{$IFNDEF WIN32}

const MAX_PATH = 144;

{$ENDIF}

var

{$IFDEF WIN32}

lpPathBuffer : PChar;

{$ENDIF}

lpbuffer : PChar;

begin

        {Get the file name buffer}

        GetMem(lpBuffer, MAX_PATH);

        {$IFDEF WIN32}

        {Get the temp path buffer}

        GetMem(lpPathBuffer, MAX_PATH); {Get the temp path}

        GetTempPath(MAX_PATH, lpPathBuffer); {Get the temp file name}

        GetTempFileName(lpPathBuffer,'tmp',0,lpBuffer);

        FreeMem(lpPathBuffer, MAX_PATH);

        {$ELSE} {Get the temp file name}

        GetTempFileName(GetTempDrive('C'),'tmp',0,lpBuffer);

        {$ENDIF} {Create a pascal string containg}

        {the temp file name and return it}

        result := StrPas(lpBuffer);

        {Free the file name buffer}

        FreeMem(lpBuffer, MAX_PATH);

end;

{Grava AVI ou Wav no arquivo PARADOX}

procedure TForm1.Button1Click(Sender: TObject);

var FileStream: TFileStream; {para ler o arquivo avi}

BlobStream: TBlobStream; {para salvar no campo blob}

begin

        Application.ProcessMessages;

        Button1.Enabled := false;

        Button2.Enabled := false;



        if OpenDialog1.Execute then

        FileStream := TFileStream.Create(OpenDialog1.FileName,fmOpenRead);

        Table1.Append;

        Table1Nome.Value := OpenDialog1.FileName;

        BlobStream := TBlobStream.Create(Table1AVI, bmReadWrite);

        BlobStream.Seek(0, soFromBeginning);

        BlobStream.Truncate;

        BlobStream.CopyFrom(FileStream, FileStream.Size);

        FileStream.Free;

        BlobStream.Free;

        Table1.Post;

        Button1.Enabled := true;

        Button2.Enabled := true;

end;

{Reproduz o que está gravado no campo Blob}

procedure TForm1.Button2Click(Sender: TObject);

var FileStream: TFileStream; {a temp file}

BlobStream: TBlobStream; {the AVI Blob}

begin

        BlobStream := TBlobStream.Create(Table1AVI, bmRead);

        if BlobStream.Size = 0 then

        begin

                BlobStream.Free;

                Exit;

        end;

        MediaPlayer1.Close; {Reset the file name}

        MediaPlayer1.FileName := ''; {Refresh the play window}

        MediaPlayer1.Display := Panel1;

        Panel1.Refresh;

        if FileName <> '' then

        DeleteFile(FileName); {Get a temp file name}

        FileName := GetTemporaryFileName; {Create a temp file stream}

        FileStream := TFileStream.Create(FileName,fmCreate or fmOpenWrite);

        FileStream.CopyFrom(BlobStream, BlobStream.Size); {Free the streams}

        FileStream.Free; BlobStream.Free;

        MediaPlayer1.FileName := filename;

        MediaPlayer1.DeviceType := dtAviVideo;

        MediaPlayer1.Open;

        MediaPlayer1.Play;

end;

// Evento OnDestroy do Form

procedure TForm1.FormDestroy(Sender: TObject);

begin

        MediaPlayer1.Close;

        MediaPlayer1.FileName := '';

        if FileName <> '' then

        DeleteFile(FileName);

end;

// Evento OnShow do Form

procedure TForm1.FormShow(Sender: TObject);

begin

        MediaPlayer1 := TMediaPlayer.Create(self);

        with MediaPlayer1 do

        begin

                Parent := self ;

                Visible := False;

        end;

        Table1.Open;

end;

// Evento OnClose do Form

procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);

begin

        Table1.Close;

end;

end.

por : Mario C. Neto