TAChart Error in tachartaxis.pas on 1514 line

[dawn]

My program use two TAChart with Two Form but use the same datasource TListChartSourceSetData from the othe form, when the form with second TAChart show, the Program Error, The error is:
    in file 'tachartaxis.pas' on line 1514: Result := (FHi - FLo) / (FMax^ - FMin^),
The FMax value is limit to 0, where change it?

The Call stack:
tachartaxis.pas      1514
tagraph.pas           616
tagraph.pas           1572
tagraph.pas           960
tagraph.pas           1511

[wp]

It's hard to find a bug without code...

Maybe you are accessing the chart's Extent too early. Call charts' Prepare method after you added the data values to the ListChartSource.

[dawn]

Thank you for your reply. Based on your suggestion, I carefully reviewed the code and yes, I accessed the data in advance. Thank you