WideString和AnsiString

var
ws: WideString;
s: AnsiString;
pw: PWideChar;
p: PAnsiChar;
begin
ws := 'ab中cd';
pw := PWideChar(ws);
s := ws;
//p:=PAnsiChar(s); 正确
//p:=PAnsiChar(String(pw));

//不正确
p := PAnsiChar(pw); //这样转换，inc(p)后显示的为00对应的为空

inc(p, 1); //
ShowMessage(p^);