var
  FCurrentTabSheet: TTabSheet;    procedure TForm1.PageControl1DragDrop(Sender, Source: TObject;
  X, Y: integer);
var
  i: integer;
  P: TPoint;
  R: Rect;
begin
  P := Point(X, Y);
  for i := 0 to PageControl1.PageCount - 1 do
  begin
    R := PageControl1.TabRect(i);
    if PtInRect(R, P) then
    begin
      if Assigned(FCurrentTabSheet) then
      begin
        if FCurrentTabSheet.PageIndex <> i then
          FCurrentTabSheet.PageIndex := i;            FCurrentTabSheet := nil;
        PageControl1.ActivePageIndex := i;
      end;
      Break;
    end;
  end;
end;    procedure TForm1.PageControl1DragOver(Sender, Source: TObject;
  X, Y: Integer; State: TDragState; var Accept: Boolean);
var
  i: integer;
begin
  if not Assigned(FCurrentTabSheet) then
  begin
    P := Point(X, Y);
    for i := 0 to PageControl1.PageCount - 1 do
    begin
      R := PageControl1.TabRect(i);
      if PtInRect(R, P) then
      begin
        FCurrentTabSheet := PageControl1.Pages[i];
        Break;
      end;
    end;
  end;
end;