delphi, send image with indy10 from client to server - delphi

Question

How I can send from a Timage (clientside) to another Timage(serverside)?
I'm using delphi XE3 with idtcpclient1, idtcpserver1 (indy10 component).
I already tried to do something but I had some trouble.
Server side:
FileStream := TFileStream.Create('ciao.jpg', fmCreate);
AContext.Connection.IOHandler.LargeStream := True;
AContext.Connection.IOHandler.ReadStream(FileStream); FileStream.Free;
image1.Picture.LoadFromFile(sname);
Client side:
idTCPClient1.IOHandler.LargeStream := True;
FileStream := TFileStream.Create('hello.jpg', fmOpenRead);
IdTCPClient1.IOHandler.Write(FileStream,0,true);
filestream.Free;

Answer 1

Example implementation for the transfer of different graphic formats.
Main issue is that you will have to create an appropriate GraphicClass.
If an image is loaded from a file the class is determinate from the file extension.
In this implemetation we add the information to the stream.
unit Unit1;
interface
uses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
Vcl.Controls, Vcl.Forms, Vcl.Dialogs, IdContext, Vcl.ExtCtrls, IdTCPConnection, IdTCPClient, IdBaseComponent,
IdComponent, IdCustomTCPServer, IdTCPServer, Vcl.StdCtrls, Vcl.Imaging.jpeg;
type
TForm1 = class(TForm)
IdTCPServer1: TIdTCPServer;
IdTCPClient1: TIdTCPClient;
Source: TImage;
Dest: TImage;
Button1: TButton;
procedure FormCreate(Sender: TObject);
procedure IdTCPServer1Execute(AContext: TIdContext);
procedure Button1Click(Sender: TObject);
private
{ Private-Deklarationen }
public
{ Public-Deklarationen }
end;
var
Form1: TForm1;
implementation
uses PNGImage;
{$R *.dfm}
//Enable transfer of different graphicformats
procedure Picture2Stream(DestStream: TMemoryStream; Picture: TPicture);
var
ms2: TMemoryStream;
TheClassName: AnsiString;
len: Byte;
begin
TheClassName := Picture.Graphic.ClassName;
len := Length(TheClassName);
DestStream.WriteBuffer(len, 1);
if len > 0 then // save GraphicClass name
DestStream.WriteBuffer(TheClassName[1], len);
ms2 := TMemoryStream.Create;
try // save graphic
Picture.Graphic.SaveToStream(ms2);
ms2.Position := 0;
if ms2.Size > 0 then
DestStream.CopyFrom(ms2, ms2.Size);
finally
ms2.Free;
end;
end;
Procedure LoadPictureFromStream(Picture: TPicture; SourceStream: TMemoryStream);
var
ms2: TMemoryStream;
len: Byte;
TheClassName: AnsiString;
Graphic: TGraphic;
GraphicClass: TGraphicClass;
begin
SourceStream.Position := 0;
SourceStream.ReadBuffer(len, 1);
SetLength(TheClassName, len);
if len > 0 then // read GraphicClass name
SourceStream.ReadBuffer(TheClassName[1], len);
GraphicClass := TGraphicClass(FindClass(TheClassName)); //(*)
if (GraphicClass <> nil) and (len > 0) then
begin
Graphic := GraphicClass.Create; // create appropriate graphic class
try
ms2 := TMemoryStream.Create;
try
ms2.CopyFrom(SourceStream, SourceStream.Size - len - 1);
ms2.Position := 0;
Graphic.LoadFromStream(ms2);
finally
ms2.Free;
end;
Picture.Assign(Graphic);
finally
Graphic.Free;
end;
end;
end;
procedure TForm1.Button1Click(Sender: TObject);
var
ms: TMemoryStream;
begin
ms := TMemoryStream.Create;
try
Picture2Stream(ms, Source.Picture);
ms.Position := 0;
IdTCPClient1.Host := '127.0.0.1';
IdTCPClient1.Port := 12345;
IdTCPClient1.Connect;
IdTCPClient1.IOHandler.LargeStream := true;
IdTCPClient1.IOHandler.Write(ms, ms.Size, true);
finally
ms.Free;
end;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
IdTCPServer1.DefaultPort := 12345;
IdTCPServer1.Active := true;
ReportMemoryLeaksOnShutDown := true;
end;
procedure TForm1.IdTCPServer1Execute(AContext: TIdContext);
var
ms: TMemoryStream;
begin
ms := TMemoryStream.Create;
try
AContext.Connection.IOHandler.LargeStream := true;
AContext.Connection.IOHandler.ReadStream(ms);
TThread.Synchronize(nil,
Procedure
begin
LoadPictureFromStream(Dest.Picture, ms);
end);
finally
ms.Free;
end;
end;
initialization
// RegisterClasses to enable FindClass (*)
RegisterClasses([TIcon, TMetafile, TBitmap, TJPEGImage, TPngImage]);
end.

Answer 2

Your question is unclear, but it seems that you're trying to transfer the content of one 'TImage' (on the client) to a TImage on the server. It's unclear whether you mean an image file or an actual TImage, though. I'm going to go with "the picture being displayed in a TImage on the client" being sent to the server.
You can use TMemoryStream instead of TFileStream. If you really mean to send the image displayed in a TImage.Picture, you can do something like this (untested):
// Server side
var
Jpg: TJpegImage;
begin
Strm := TMemoryStream.Create;
try
Strm.Position := 0;
AContext.Connection.IOHandler.LargeStream := True;
AContext.Connection.IOHandler.ReadStream(Strm);
Strm.Position := 0;
Jpg := TJpegImage.Create;
try
Jpg.LoadFromStream(Strm);
Image1.Picture.Assign(Jpg);
finally
Jpg.Free;
end;
finally
Strm.Free;
end;
end;
// Client side
IdTCPClient1.IOHandler.LargeStream := True;
Strm := TMemoryStream.Create;
try
Image1.Picture.Graphic.SaveToStream(Strm);
Strm.Position := 0;
IdTCPClient1.IOHandler.Write(Strm, 0, True);
finally
Strm.Free;
end;
If that's not what you want, edit your question so we can understand what you're trying to do. (Don't tell us in comments, but actually edit your question to make it more clear.)