delphi - 为什么Delphi中BitMap的传输顺序相反？

Question

单击该按钮时，图像应从 richedit1 传输到 richedit2 并按顺序显示，反之亦然。如何修复它？下面是代码。

procedure TForm1.Button1Click(Sender: TObject);
begin
  if OpenPictureDialog1.Execute then
  begin
    Image1.Picture.LoadFromFile(OpenPictureDialog1.FileName);
    InsertBitmapToRE(RichEdit1.Handle, Image1.Picture.Bitmap.Handle);
  end;
end;

Function MAP_LOGHIM_TO_PIX(Const Val: Integer; Const Log: Integer): Integer;
Const
  HIMETRIC_PER_INCH=2540;
Begin
  Result:=MulDiv(Val, Log, HIMETRIC_PER_INCH);
End;

Function MAP_LOGHIMPT_TO_PT(Const Val: TPoint; Const Handle: HWND = 0): TPoint;
Var
  DC: HDC;
Begin
  DC:=GetDC(Handle);
  Result.X:=MAP_LOGHIM_TO_PIX(Val.X, GetDeviceCaps(DC, LOGPIXELSX));
  Result.Y:=MAP_LOGHIM_TO_PIX(Val.Y, GetDeviceCaps(DC, LOGPIXELSY));
  ReleaseDC(Handle, DC);
End;

procedure TForm1.Button2Click(Sender: TObject);
Var
  IREO: IRichEditOle;
  OleClientSite: IOleClientSite;
  ReObject: TReObject;
  I: Integer;
  ViewObject2: IViewObject2;
  Rc: TRect;
  Path:String;
  bmp:TBitmap;
  Pt: TPoint;
begin
  Path:='C:\temp\richedit\';
  SendMessage(RichEdit1.Handle, EM_GETOLEINTERFACE, 0, Longint(@IREO));
  IREO.GetClientSite(OleClientSite);
  For I:=IREO.GetObjectCount-1 Downto 0 Do
  Begin
    ZeroMemory(@ReObject, SizeOf(ReObject));
    ReObject.cbStruct:=SizeOf(ReObject);
    If Succeeded(IREO.GetObject(I, ReObject, $00000001)) Then
    If Succeeded(ReObject.poleobj.QueryInterface(IViewObject2, ViewObject2)) Then
    Begin
      ViewObject2.GetExtent(DVASPECT_CONTENT, -1, Nil, Pt);
      Pt:=MAP_LOGHIMPT_TO_PT(Pt, RichEdit1.Handle);
      bmp:=TBitmap.Create;
      Bmp.Height := Pt.Y;
      Bmp.Width := Pt.X;
      SetRect(Rc, 0, 0, Bmp.Width, Bmp.Height);
      OleDraw(ReObject.poleobj, DVASPECT_CONTENT, bmp.Canvas.Handle, Rc);
      bmp.SaveToFile(Path+'Img'+IntToStr(I+1)+'.bmp');
      InsertBitmapToRE(RichEdit2.Handle, bmp.Handle);
    End
    Else
      ShowMessage('Error: Can''t get IViewObject2');
  End;
end;

截图

Answer 1

在 for 循环中使用 downto 0 效率很高，但会反向计数，因此并不总是可取的。出现这种情况是因为您使用循环变量作为索引并且需要特定的处理顺序。

对于 I:= 0 到 IREO.GetObjectCount-1 执行