CAD实现文档坐标到视区坐标的转换（com接口Delphi语言）

procedure TForm1.Button1Click(Sender: TObject);

 var

  pRet: MxDrawResbuf;

  h, w: double;

  ptMin        : IMxDrawPoint;

  ptMax       : IMxDrawPoint;

  ptOle        : OleVariant;

  begin

  ifdlgSave1.Execute then

  begin

    pRet := MxDrawResbuf(MxDrawX1.Call('Mx_GetMcDbDatabaseBound', ''));

    ifpRet.AtString(0) = 'Ok'then

    begin

      ptMin :=  CoMxDrawPoint.Create();

      ptMin.Set_x(pRet.AtDouble(1));

      ptMin.Set_y(pRet.AtDouble(2));

      ptOle := MxDrawX1.DocToViewCoord(ptMin);

      ptMin:=IMxDrawPoint(IDisPatch(ptOle));

      ptMax :=  CoMxDrawPoint.Create();

      ptMax.Set_x(pRet.AtDouble(3));

      ptMax.Set_y(pRet.AtDouble(4));

      ptOle := MxDrawX1.DocToViewCoord(ptMax);

      ptMax:=IMxDrawPoint(IDisPatch(ptOle));

      MxDrawX1.ViewColor := clWhite;

      w := ptMax.Get_x();

      w := w - ptMin.Get_x() + 1;

      h := ptMax.Get_y();

      h := ptMin.Get_y() - h  + 1;

      ifnot MxDrawX1.SaveJpgFile(dlgSave1.FileName, Round(w), Round(h),0) then

        Showmessage('失败')

      else

        Showmessage('成功');

    end;

  end;

  end;