Delphi TeeChart 绘制在 canvas 上

Question

I am using delphi 10.3 TeeChart to map out some points.

After mapping these points out, I want to generate lines between these points.

So basically a line from Point A to Point B

chart1.Canvas.Pen.Color := ClYellow;
chart1.Canvas.Pen.Width := 2;
chart1.Canvas.MoveTo(Chart1.Axes.Bottom.CalcXPosValue(chart1.Series[0].XValues[WayPoint]),Chart1.Axes.left.CalcYPosValue(Chart1.Series[0].YValues[WayPoint]));
chart1.Canvas.LineTo(Chart1.Axes.Bottom.CalcXPosValue(chart1.Series[0].XValues[WayPoint+1]),Chart1.Axes.left.CalcYPosValue(Chart1.Series[0].YValues[WayPoint+1]));

That code is run on the AfterDraw event of chart1, It is run under a for I:= 1 to Points (number of waypoints).

The Result I get is as follows:

Any help or suggestions would be great !

Answer 1

if I is the same as Waypoint , note that series value lists are indexed from 0 to NPoints - 1 , so for I:= 1 to Points looks strange.

Moreever, to connect points, you need NPoints - 1 segments, so loop should count from 0 to NPoint - 2 (to avoid out of array at WayPoint+1 )

And the main doubt - why do you draw lines "by hands" while TChart was intended for this purpose?