Question

I have an (Delphi XE2) VCL app containing an object TDownloadUrl (VCL.ExtActns) to check several webpages, so I wonder if there is an equivalent object in FireMonkey, ’cause I wanna take advantage of rich features from this new platform.

A Firemonkey app demo using threads would appreciate. Thanks in advance.

Answer 1

Actions don’t exist yet with FireMonkey.

BTW, you can create the same behavior with a code like this:

IdHTTP1: TIdHTTP;

…

procedure TForm2.MenuItem1Click(Sender: TObject);
const
  FILENAME = 'C:\Users\Whiler\Desktop\test.htm';
  URL      = 'http://stackoverflow.com/questions/7491389/firemonkey-and-tdownloadurl';
var
//  sSource: string;
  fsSource: TFileStream;
begin
  if FileExists(FILENAME) then
  begin
    fsSource := TFileStream.Create(FILENAME, fmOpenWrite);
  end
  else
  begin
    fsSource := TFileStream.Create(FILENAME, fmCreate);
  end;

  try
    IdHTTP1.Get(URL, fsSource);
  finally
    fsSource.Free;
  end;
//  sSource := IdHTTP1.Get(URL);
end;

The commented lines can replace the others if you just need the source in memory…

---

---

If you want to use a thread, you can manage it like this:

unit Unit2;

interface

uses
  System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,
  FMX.Types, FMX.Controls, FMX.Forms, FMX.Dialogs, IdBaseComponent, IdComponent, IdTCPConnection, IdTCPClient, IdHTTP, FMX.Menus;

type
  TDownloadThread = class(TThread)
  private
    idDownloader: TIdHTTP;
    FFileName   : string;
    FURL        : string;
  protected
    procedure Execute; override;
    procedure Finished;
  public
    constructor Create(const sURL: string; const sFileName: string);
    destructor  Destroy; override;
  end;
type
  TForm2 = class(TForm)
    MenuBar1: TMenuBar;
    MenuItem1: TMenuItem;
    procedure MenuItem1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form2: TForm2;

implementation

{$R *.fmx}

procedure TForm2.MenuItem1Click(Sender: TObject);
const
  FILENAME = 'C:\Users\Whiler\Desktop\test.htm';
  URL      = 'http://stackoverflow.com/questions/7491389/firemonkey-and-tdownloadurl';
var
//  sSource: string;
  fsSource: TFileStream;
begin
  TDownloadThread.Create(URL, FILENAME).Start;
end;

{ TDownloadThread }

constructor TDownloadThread.Create(const sURL, sFileName: string);
begin
  inherited Create(true);
  idDownloader := TIdHTTP.Create(nil);
  FFileName       := sFileName;
  FURL            := sURL;
  FreeOnTerminate := True;
end;

destructor TDownloadThread.Destroy;
begin
  idDownloader.Free;
  inherited;
end;

procedure TDownloadThread.Execute;
var
//  sSource: string;
  fsSource: TFileStream;
begin
  inherited;
  if FileExists(FFileName) then
  begin
    fsSource := TFileStream.Create(FFileName, fmOpenWrite);
  end
  else
  begin
    fsSource := TFileStream.Create(FFileName, fmCreate);
  end;

  try
    idDownloader.Get(FURL, fsSource);
  finally
    fsSource.Free;
  end;
  Synchronize(Finished);
end;

procedure TDownloadThread.Finished;
begin
  // replace by whatever you need
  ShowMessage(FURL + ' has been downloaded!');
end;

end.