拖管记录

拖管记录

DELPHI10.4开始支持 拖管记录。

unit Unit1;

interface

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

type
  TMyRecord = record
    Value: Integer;
    class operator Initialize (out Dest: TMyRecord);
    class operator Finalize(var Dest: TMyRecord);
  end;

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

var
  Form1: TForm1;

implementation

{$R *.dfm}

class operator TMyRecord.Initialize (out Dest: TMyRecord);
begin
  Dest.Value := 10;
  form1.Memo1.Lines.Add('created' + IntToHex (Integer(Pointer(@Dest))));
end;

class operator TMyRecord.Finalize(var Dest: TMyRecord);
begin
  form1.Memo1.Lines.Add('destroyed' + IntToHex (Integer(Pointer(@Dest))));
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  var r: TMyRecord;
  memo1.Lines.Add(r.Value.ToString);
end;

end.

　　测试：

created0019F398
10
destroyed0019F398