Steema Central

Hello,

i've a problem with the TeeChartScrollBar. I've got a simple dataset with two fields: X (TDateTime) and Y (Integer). The minimum of X is today, the maximum is 100 days from today. I've connected a TeeChartScrollbar to the chart with the following properties: Axis = sbDefault; Align = alBottom; Kind = sbHorizontal. When I run the application everything looks good, but when i zoom in on the chart the values on the X-axis change to dates around 1900. The same things happened when I changed the X-axis from TDateTime to integer values, but it only occurs with large numbers (>30000).

I've tried to track the problem and it seems that the ScrollAxis(Axis:TChartAxis) inline procedure sets uncorrect values for my X-axis.

Can you explain how I can fix this problem? Im using TeeChart Pro 7.12. If necessary I can provide you with an example which you can run "as is".

Greetings,

Marcel.

Hi Marcel,

This is because TChartScrollBar is not using DateTime range. You could try setting its maximum to 50000 at designtime and then use this code:
Hope this helps!

narcis wrote:Hi Marcel,

This is because TChartScrollBar is not using DateTime range. You could try setting its maximum to 50000 at designtime and then use this code:

Code: Select all

uses DateUtils, Math;

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
var i: integer;
begin
  Series1.XValues.DateTime:=true;

  for i:=0 to 100 do
  begin
    Series1.AddXY(Today + i, random);
  end;

  ChartScrollBar1.Min := Trunc(Series1.MinXValue);
  ChartScrollBar1.Max := Trunc(Series1.MaxXValue);

  Chart1.Title.Text[0]:=IntToStr(ChartScrollBar1.Max);
end;

Hope this helps!

Hi Narcis,

thanks for the quick response. Your suggestion works to a certain extent in my sample application. However it can't get it to right in my main application. Ill try to see if there's a difference between the two.

Thanks,

Marcel.

Hi Marcel,

Your problem seems the same as described here. For now, the solution is using TScrollBar instead of TChartScrollBar. I have sent you an e-mail with and example using TScrollBar.