读文件到十六进制的函数

{函数}
function ReadFileToHex(FileName: string): string;
var
  b: Byte;
begin
  Result := '' ;
  if not FileExists(FileName) then Exit;
  with TMemoryStream.Create do begin
    LoadFromFile(FileName);
    Position := 0 ;
    while Position < Size do
    begin
      ReadBuffer(b, 1 );
      Result := Result + Format( '%.2x ' , [b]);
    end;
    Trim(Result);
    Free;
  end;
end;

{调用}
procedure TForm1.Button1Click(Sender: TObject);
var
  str: string;
begin
  str := ReadFileToHex( 'c:\temp\test.txt' );
  ShowMessage(str);
end;