BorlandTalk.com

Tumurbaatar S. · Guest

Is it possible to force an axis grid drawing after a series drawing?
I use TAreaSeries and it's colored area overlaps grid lines,
but I need the grid was visible. Any ideas?
Also, my series X values are date/time and XScreenToValue(N)
method returns date/time which corresponds to Nth pixel.
This date/time value shows only place on the X axis, but I need
a _nearest_ _existing_ point's (relative to X axis) X value. E.g.
my series has points with X values ..., 00:05, 00:08... and
above XScreenToValue(N) method returns 00:07. The point with
such date/time value does not exist. So I need to locate the nearest
point in a series: 00:08. How?

Damon Chandler (TeamB) · Guest

Hi,
For the gridlines to appear on top of the Series, you can call the
Draw() method of your chart's axes from within an OnAfterDraw event
handler...

void __fastcall TForm1::Chart1AfterDraw(TObject *Sender)
{
Chart1->LeftAxis->Draw(false);
Chart1->BottomAxis->Draw(false);
}

For the XScreenToValue() issue, have you tried looping through your list
of x-values (via the XValues property of the series) to find the nearest
neighbor? This should work if your x-values are monotonic.

Good luck,
--
Damon (TeamB)
C++Builder Developer's Journal
http://bcbjournal.com
BCB Commonly Asked Questions
http://bcbjournal.com/bcbcaq

Tumurbaatar S. wrote: