Goal:
Show the title of a series on a label when the user clicked on a box.
IDE: Delphi XE3

The OnClickSeries event in the TChart component with TBoxSeries is not always fired and sometimes with the wrong "Series" parameter.

When the following code is executed and we click on the boxes some different effects can be observed:
- Label get the right title
- Event is not triggered (please have a look to the time signature at the lable.caption)
- Lebel get the wrong title
- Same series get different result at different clicks

Please click between different boxes.


Code to reproduces
Add a TChart, a Button and a Label on a VCL-Form without any property changes

Fill two events with following code:


// Create some boxplots and fill them with values
procedure TForm1.Button1Click(Sender: TObject);
var
  NewBoxSerie: TBoxSeries;
  i: Integer;
  w: Double;
  x: Integer;
  j: Integer;
  xSeriesCount: Integer;
begin

  Chart1.SeriesList.Clear;
  Chart1.Legend.Items.Clear;


  xSeriesCount:=5;

  // Calculate the distance between the box plots
  w:=100 / (xSeriesCount + 1);

  for i := 0 to xSeriesCount - 1 do
  begin

    NewBoxSerie:=TBoxSeries.Create(Chart1);

    // Create some nice box plot values
    NewBoxSerie.AddX(1);
    NewBoxSerie.AddX(2);

    NewBoxSerie.AddX(10);
    NewBoxSerie.AddX(12);
    NewBoxSerie.AddX(13);
    NewBoxSerie.AddX(14);
    NewBoxSerie.AddX(15);

    NewBoxSerie.AddX(25);
    NewBoxSerie.AddX(26);

    NewBoxSerie.Title:=IntToStr(Chart1.SeriesCount);
    Chart1.AddSeries(NewBoxSerie);

    // Set the position of the box plot for better viewing
    NewBoxSerie.Position:=(w / 2) + (w * i);
    NewBoxSerie.Box.Color:=NewBoxSerie.Color;

  end;


end;


// Show the user the title of the clicked series 
procedure TForm1.Chart1ClickSeries(Sender: TCustomChart; Series: TChartSeries;
  ValueIndex: Integer; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin

  if Assigned(Series) then

    Label1.Caption:='Clicked on series ' + Series.Title +
                    // Added the time stamp to see that the event is not always triggered
                    ' at: ' + FormatDateTime('NN:SS', Now)
  else
    Label1.Caption:='Series not assigned';

end;