Generic record

[bernhard_LA]

@himitsu :

warum benötige ich

Zitat:

class function ByteArrayToMyRecord(ABuffer: TBytes): TRecordType; static;

anbei meine aktuelle Lösung, scheint zu spielen ... im simplen Quick&Dirty - Test

Delphi-Quellcode:

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    Memo1: TMemo;
    procedure Button1Click(Sender: TObject);
  private
    { Private-Deklarationen }
  public
    { Public-Deklarationen }
  end;



type

  TMyRecordA = record
    Details: string[255];
    FileName: string[255];
    FileDate: TDateTime;
    FileSize: Integer;
    Recordsize: Integer;
  end;

  TMyRecordB = record
    Details: string[255];
    x: Real;
    y: Real;
    z: Real;
  end;


  TMyRecordC = record
    FileDate: TDateTime;
    FileSize: Integer;
    x: Real;
    y: Real;
    z: Real;
  end;


  TGenericRecord<TRecordType> = class


    value  :  TRecordType ;

    /// <summary>
    /// Convert Byte to Record , outputtype : TRecordType
    /// </summary>
    /// <param name="ABuffer">
    /// Byte Array
    /// </param>
    function ByteArrayToMyRecord(ABuffer: TBytes): TRecordType;
    // class function ByteArrayToMyRecord(ABuffer: TBytes): TRecordType; static;

    /// <summary>
    /// Store a Record into a BYTE Array
    /// </summary>
    /// <param name="aRecord">
    /// adjust this record definition to your needs
    /// </param>
    function MyRecordToByteArray(aRecord: TRecordType): TBytes;
    // class function MyRecordToByteArray(aRecord: TRecordType): TBytes; static;

  end;


var
  Form1: TForm1;

implementation

{$R *.dfm}



function TGenericRecord<TRecordType>.MyRecordToByteArray(aRecord: TRecordType): TBytes;
var
  LSource: PAnsiChar;
begin
  LSource := PAnsiChar(@aRecord);
  SetLength(Result, SizeOf(TRecordType));
  Move(LSource[0], Result[0], SizeOf(TRecordType));
end;

function TGenericRecord<TRecordType>.ByteArrayToMyRecord(ABuffer: TBytes): TRecordType;
var
  LDest: PAnsiChar;
begin
  LDest := PAnsiChar(@Result);
  Move(ABuffer[0], LDest[0], SizeOf(TRecordType));
end ;


procedure TForm1.Button1Click(Sender: TObject);
var  a_record   :  TGenericRecord<TMyRecordA>;
     b_record   :  TGenericRecord<TMyRecordB>;
     c_record   :  TGenericRecord<TMyRecordC>;


     ABuffer   :  TBytes;
begin


     ///  create class
     a_record :=TGenericRecord<TMyRecordA>.Create;
     b_record :=TGenericRecord<TMyRecordB>.Create;
     c_record :=TGenericRecord<TMyRecordC>.Create;




     /// einb paar werte zuweisen .....
     a_record.value.Details := '#1 bla bla';
     a_record.value.FileName := '#2 bla bla';
     a_record.value.Recordsize := 100;
     a_record.value.FileSize := 222;


     b_record.value.x := 1;
     b_record.value.y := 2;
     b_record.value.z := 3;



      ///  im buffer daten zwischenlagern 
     ABuffer :=  a_record.MyRecordToByteArray(a_record.value);


     /// löschen oder mit anderen daten arbeiten 
     a_record.value.Details := '.....';
     a_record.value.FileName := '----';
     a_record.value.Recordsize := -1;
     a_record.value.FileSize := -2;



     //  Daten wieder aus dem Buffer zurücklesen 
     a_record.value := a_record.ByteArrayToMyRecord(ABuffer);


     /// alte daten sind wieder da :-) 
     memo1.lines.add( a_record.value.Details) ;
     memo1.lines.add( a_record.value.Filename) ;

     ///  free class
     a_record.Free;
     b_record.Free;
     c_record.Free;

end;

end