record lesen/speichern in D8

[Mario]

Da das ReadBuffer in .Net nicht mehr mit Records funktioniert, muss man mit Serialisierung arbeiten. Hier ein kleines Beispiel:

Delphi-Quellcode:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, System.ComponentModel, Borland.Vcl.StdCtrls,
  System.Runtime.Serialization.Formatters.Binary;

type
  [Serializable()]
  TMyRec = packed record
    FValue1 : Double;
    FValue2 : String;
  end;

  [Serializable()]
  TData = class
  private
    FValue1,
    FValue2: String;
    FRec: TMyRec;
  [NonSerialized()] FValue3: String;
  end;

  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    procedure Button2Click(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private-Deklarationen }
  public
    { Public-Deklarationen }
  end;

var
  Form1: TForm1;

implementation

{$R *.nfm}

procedure TForm1.Button1Click(Sender: TObject);
var aData: TData;
    aRec: TMyRec;
    aFileStream: TFileStream;
    aFormatter: BinaryFormatter;
begin
  aData := TData.Create;
  aData.FValue1 := 'Wert 1';
  aData.FValue2 := 'Wert 2';
  aData.FValue3 := 'Wert 3';
  aData.FRec.FValue1 := 0.123;
  aData.FRec.FValue2 := 'abc';
  aRec.FValue1 := 0.123;
  aRec.FValue2 := 'abc';

  aFileStream := TFileStream.Create('test.dat', fmCreate);
  aFormatter :=  BinaryFormatter.Create;
  aFormatter.Serialize(aFileStream, aData);

  aFileStream := TFileStream.Create('test2.dat', fmCreate);
  aFormatter :=  BinaryFormatter.Create;
  aFormatter.Serialize(aFileStream, aRec);
end;

procedure TForm1.Button2Click(Sender: TObject);
var aData: TData;
    aRec: TMyRec;
    aFileStream: TFileStream;
    aFormatter: BinaryFormatter;
begin
  aFileStream := TFileStream.Create('test.dat', fmOpenRead);
  aFormatter :=  BinaryFormatter.Create;

  aData := TData(aFormatter.Deserialize(aFileStream));

  ShowMessage(aData.FValue1);
  ShowMessage(aData.FValue2);
  ShowMessage(aData.FValue3);

  aFileStream := TFileStream.Create('test2.dat', fmOpenRead);
  aFormatter :=  BinaryFormatter.Create;

  aRec := TMyRec(aFormatter.Deserialize(aFileStream));
  ShowMessage(aRec.FValue1.ToString);
  ShowMessage(aRec.FValue2);
end;

end.