Delphi Firemonkey XE8-如何使用DataSnap正确发送/接收图像

Question

I'm developing an Android app using Delphi Firemonkey XE8. I need to send images to the server, where a service has to receive and store them.

So far I was able to send and receive simple classes, like this:

TCliente = class
        private
          pCodigo: integer;
          pNomeRazaoSocial: string;
          pApelidoFantasia: string;
          pCPFCNPJ: string;
        public
          property Codigo: integer read pCodigo write pCodigo;
          property NomeRazaoSocial: string read pNomeRazaoSocial write pNomeRazaoSocial;
          property ApelidoFantasia: string read pApelidoFantasia write pApelidoFantasia;
          property CPFCNPJ: string read pCPFCNPJ write pCPFCNPJ;
end;

The bitmap images are stored in a SQLite database as BLOB. I need to send those images to the server and, as soon as they get there, save them in the MySQL database, in BLOB fields as well.

I need to do it using DataSnap.

Everything I tried so far hasn't worked.

Answer 1

I resolved the issue in this way:

var
  strImagem: TMemoryStream;
  B: TBitmap;
begin
//create TBitmap of correct size
  B := TBitmap.Create(rectSign.Width div 2, rectSign.Height div 2);
  B.Clear(TAlphaColorRec.White);

//move source image to the created TBitmap
  if B.Canvas.BeginScene then
    try
      layoutPhoto.PaintTo(B.Canvas, TRectF.Create(, , B.Width, B.Height));
    finally
      B.Canvas.EndScene;
    end;

  try
//create stream for image
    strImagem := TMemoryStream.Create;
//load the TBitmap to it
    B.SaveToStream(strImagem);
//return cursor of stream to the beginning
    strImagem.Position := ;

    dm.qMDevice.SQL.Text := 'UPDATE Orders SET PHOTO = :PHOTO WHERE ROWID = :RowId';
    dm.qMDevice.ParamByName('RowId').AsInteger := SourceROW;
//load to the query the image from our stream
    dm.qMDevice.ParamByName('PHOTO').LoadFromStream(strImagem, ftBlob);
    dm.qMDevice.ExecSQL;
    dm.qMDevice.Close;
  except
    on e: Exception do
      Toast('Unable to save photo #7702:'#13#10 + e.Message);
  end;

//release resources
  FreeAndNil(B);
  FreeAndNil(strImagem);
end;

Maybe not very elegant, but it works.