TStream与内存段相互转换

刚才有人问起..顺手写的.
他是用于DLL,所以我多写了2个函数.在DLL里提供内存指针输出,一定要记得提供相应的内存释放函数.
有借有还,再借不难...
老规矩..下面是demo

var
  MS: TMemoryStream;
  bytes: PByte;
  size: Integer;
begin
  MS := TMemoryStream.Create;
  MS.LoadFromFile('d:\1.rar');
  size := StreamToBytes(MS, bytes);

  MS.Clear;

  BytesToStream(bytes, size, MS, True);
  MS.SaveToFile('d:\2.rar');
end;

　　

procedure GetBytes(out Bytes: PByte; ByteSize: Integer);
begin
  GetMem(Bytes, ByteSize);
end;

//如果是用在DLL里,一定要记得Export这个函数!!
procedure FreeBytes(Bytes: PByte);
begin
  FreeMem(Bytes);
end;

procedure BytesToStream(Bytes: PByte; ByteSize: Integer;
  Stream: TStream; NeedFree: Boolean);
begin
  Stream.Size := 0;
  Stream.Write(Bytes^, ByteSize);
  //是否要释放Bytes?
  if NeedFree then
    FreeBytes(Bytes);
end;

function StreamToBytes(Stream: TStream;
  out Bytes: PByte): Integer;
begin
  Result := Stream.Size;
  GetBytes(Bytes, Result);
  Stream.Seek(0, soFromBeginning);
  Stream.Read(Bytes^, Result);
end;