Delphi/Lazarus: Change Order of TabSheets on PageControl at runtime

Question: We have a TPageControl, on which there are positioned some TabSheets. At the start of the program, those tabs have a specific arrangement and we would like to change this arrangement or the order of the tabs during the runtime of our program.

Solution: Via the property PageIndex, it is possible to determine the position of each TabSheet on a PageControl.

procedure TForm1.Button1Click(Sender: TObject);
begin
  TabSheet3.PageIndex:=0;
  TabSheet2.PageIndex:=1;
  TabSheet1.PageIndex:=2;
  TabSheet0.PageIndex:=3;
end; 

In the example, the order of the TabSheets "TabSheet0" to "TabSheet3" is reversed, so that first, "TabSheet0" is located at the first position and after running the code, "TabSheet3" is located at the first position and "TabSheet0" is at the last position.