Steema Central

I have a strange problem. (Delphi 7)

I have an mdichild with a single form on it. The form contains a tchart with align=alClient.

I am doing some drawing on the tchart in the onAfterDraw event. If I do chart.invalidate, the drawing works perfectly.

However, if I do this
var
tst:tRect
begin

tst:=chart1.boundsRect;
invalidaterect(chart1.handle,@tst,false)
end;

nothing happens. invalidateRect is a windows API command that allows you to invalidate only certain portions of a window. Since I chose the whole boundsRect, it should repaint the whole window. but it doesn't.

Of course, eventually, I only want to repaint small parts of the window, but can you tell me how to properly use invalidateRect with Tchart.

Hi David,

it does not work with TChart component if it's double-buffered. To make it work you have to set the BufferedDisplay property to false :

Chart1.BufferedDisplay:=False;

Thank you pep, I will give that a try