Firemonkey and TDownloadUrl - delphi

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.

Answer 2

Regarding this:
A Firemonkey app demo using threads would appreciate.
You can find a FireMonkey demo which is using Thread here: https://radstudiodemos.svn.sourceforge.net/svnroot/radstudiodemos/branches/RadStudio_XE2/FireMonkey/FireFlow/MainForm.pas
type
TImageThread = class(TThread)
private
FImage: TImage;
FTempBitmap: TBitmap;
FFileName: string;
protected
procedure Execute; override;
procedure Finished;
public
constructor Create(const AImage: TImage; const AFileName: string);
destructor Destroy; override;
end;
...
TImageThread.Create(Image, Image.TagString).Start;
if you don't have this demo in your sample directory, you can check it out from the subversion repository used in the link above.

Answer 3

You can using this code.
unit BitmapHelperClass;
interface
uses
System.Classes, FMX.Graphics;
type
TBitmapHelper = class helper for TBitmap
public
procedure LoadFromUrl(AUrl: string);
procedure LoadThumbnailFromUrl(AUrl: string; const AFitWidth, AFitHeight: Integer);
end;
implementation
uses
System.SysUtils, System.Types, IdHttp, IdTCPClient, AnonThread;
procedure TBitmapHelper.LoadFromUrl(AUrl: string);
var
_Thread: TAnonymousThread<TMemoryStream>;
begin
_Thread := TAnonymousThread<TMemoryStream>.Create(
function: TMemoryStream
var
Http: TIdHttp;
begin
Result := TMemoryStream.Create;
Http := TIdHttp.Create(nil);
try
try
Http.Get(AUrl, Result);
except
Result.Free;
end;
finally
Http.Free;
end;
end,
procedure(AResult: TMemoryStream)
begin
if AResult.Size > 0 then
LoadFromStream(AResult);
AResult.Free;
end,
procedure(AException: Exception)
begin
end
);
end;
procedure TBitmapHelper.LoadThumbnailFromUrl(AUrl: string; const AFitWidth,
AFitHeight: Integer);
var
Bitmap: TBitmap;
scale: Single;
begin
LoadFromUrl(AUrl);
scale := RectF(0, 0, Width, Height).Fit(RectF(0, 0, AFitWidth, AFitHeight));
Bitmap := CreateThumbnail(Round(Width / scale), Round(Height / scale));
try
Assign(Bitmap);
finally
Bitmap.Free;
end;
end;
end.