DELPHI 中pwidechar 与String

var

 s,s1: string;    

pw: PWideChar;    

begin      

  s:='hello worldxxxx';     

  GetMem(pw,2*length(s)+2);    

  pw:=StringToWideChar(s,pw,length(s)+2);    

  s1:=WideCharToString(pw);    

  edit1.Text:=s1;

    freemem(pw);    

end;