Put "bytes" in a Unicode string declared variable in Delphi 2009

unit Unit1;
 
interface
 
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ComCtrls, StrUtils, StdCtrls, ExtCtrls;
 
type
  TForm1 = class(TForm)
    Memo1: TMemo;
    Button1: TButton;
    Button2: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    FData : Array[0..1000] of Byte;
    FDataPos : Integer;
  end;
 
var
  Form1: TForm1;
 
implementation
 
{$R *.dfm}
 
// Returns the index in the string where the data was inserted...
Function AddBytesToUnicodeString(var Data; Count : Integer; var AText : String) : Integer;
Begin
  Result := Length(AText)+1;
  SetLength(AText, Result+((Count+1) shr 2));
  Move(Data, AText[Result], Count);
End;
 
Procedure GetBytesFromUnicodeString(AText : String; Index : Integer; var Data; Count : Integer);
Begin
  Move(AText[Index], Data, Count);
End;
 
procedure TForm1.FormCreate(Sender: TObject);
var i : Integer;
begin
  // Create a block of random data...
  Randomize;
  for i := 0 to Length(FData)-1 do
    FData[i] := Random(255);
end;
 
// Move FData into Memo1.Text
procedure TForm1.Button1Click(Sender: TObject);
var AText : string;
begin
  AText := Memo1.Text;
  FDataPos := AddBytesToUnicodeString(FData[0], Length(FData), AText);
  Memo1.Text := AText;
end;
 
// Get the Data from the memo into ReadData block
procedure TForm1.Button2Click(Sender: TObject);
var i : Integer;
    ReadData : Array of Byte;
begin
  SetLength(ReadData, Length(FData));
  try
    GetBytesFromUnicodeString(Memo1.Text, FDataPos, ReadData[0], Length(FData));
    // Verify the data we read against the source... 
    for i := 0 to Length(ReadData)-1 do
      if ReadData[i] <> FData[i] then
        raise Exception.Create('Data is not similar: '+IntToStr(i));
    ShowMessage('Data read and restored successfully.');
  finally
    ReadData := nil; 
  end;
end;
 
end.
                                              

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