Delphi TMemoryStream写入到字符串和字符串写入到流

var
lvStream:TMemoryStream;
s:AnsiString;
p: PAnsiChar;
begin
lvStream:= TMemoryStream( pvObject);
GetMem(p, lvStream.Size + 1);
FillChar(p^, lvStream.Size, 0);
Move(lvStream.Memory^,p^,lvStream.Size);
s:=p;
FreeMem(p);

var
  lvStream:TMemoryStream;
  s:AnsiString; 
begin
   s:=‘abcdefghjkimoop‘;
   lvStream.Write(s[1], Length(s));

    lvStream.Position := 0;
end;