Read points from TLineSeries

[LemonParty]

I have a line series. I added there few points over method AddXY. How can I read these points back?

[wp]

What do you mean? Read the values by code? Then call Series.XValue[point_index] and Series.YValue[point_index]. Or read the values by pointing or clicking at them with the mouse? In this case use a TDatapointHintTool, a TDatapointClickTool or a TDataPointCrosshairTool - see https://wiki.lazarus.freepascal.org/TAChart_Tutorial:_Chart_Tools, https://wiki.lazarus.freepascal.org/TAChart_documentation#Tools, or the sample project "tools" in the "demo" folder of the TAChart installation.

[LemonParty]

Thank you for responce.
The second question remain.
User click in random place on graph. How can I determine the coordinate of click?

[wp]

Write a handler for the chart's OnMouseDown event in which you convert the mouse coordinates to the chart's "graph coordinates" (Chart.ImageToGraph):

Code: Pascal  [Select][+][-]

1. uses
2.   TAChartUtils;
3.  
4. procedure TForm1.Chart1MouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
5. var
6.   P: TDoublePoint;
7. begin
8.   P := Chart1.ImageToGraph(Point(X, Y));
9.   ShowMessage(Format('MouseDown at %d/%d --> %.3f/%.3f', [X, Y, P.X, P.Y]));
10. end;

[LemonParty]

Thank you. It works.