how to draw red line on teechart of delphi - delphi-7

Question

I need to draw teechart look like the picture.
how to draw red line on teechart of delphi?

Answer 1

In addition to a TLineSeries for the line data, add a TFastLineSeries with the Stairs property set to true to create the dashed lines that mark the specified data point. (An image of the resulting chart is attached at the end of answer).
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ExtCtrls, TeeProcs, TeEngine, Chart, Series;
type
TForm1 = class(TForm)
Chart1: TChart;
LineSeries: TLineSeries;
StairSeries: TFastLineSeries;
procedure FormCreate(Sender: TObject);
procedure StairSeriesGetMarkText(Sender: TChartSeries; ValueIndex: Integer; var MarkText: string);
private
BottomMinimum : double;
LeftMinimum : double;
DataPoint : double;
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
function Fx(x : double) : double;
begin
Result := ((x - 1.5) * 20) + 17;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
LineSeries.Clear;
StairSeries.Clear;
LeftMinimum := 12;
BottomMinimum := 1.25;
DataPoint := 1.68;
LineSeries.AddXY( 1.5, Fx(1.5) );
LineSeries.AddXY( 1.6, Fx(1.6) );
LineSeries.AddXY( 1.7, Fx(1.7) );
StairSeries.AddXY( BottomMinimum, Fx(DataPoint) );
StairSeries.AddXY( DataPoint, Fx(DataPoint) );
StairSeries.AddXY( DataPoint, LeftMinimum );
Chart1.LeftAxis.SetMinMax( LeftMinimum, LeftMinimum + 12 );
Chart1.BottomAxis.SetMinMax( BottomMinimum, BottomMinimum + 0.75 );
end;
procedure TForm1.StairSeriesGetMarkText(Sender: TChartSeries; ValueIndex: Integer; var MarkText: string);
begin
if valueIndex = 0 then
MarkText := ' '+Format('%5.2n',[ Fx(DataPoint) ])
else if valueIndex = 1 then
MarkText := ''
else
MarkText := ' '+Format('%5.2n',[ DataPoint ])
end;
end.
The DFM:
object Form1: TForm1
Left = 234
Top = 127
Width = 602
Height = 533
Caption = 'Form1'
Color = clBtnFace
Font.Charset = DEFAULT_CHARSET
Font.Color = clWindowText
Font.Height = -11
Font.Name = 'Tahoma'
Font.Style = []
OldCreateOrder = False
OnCreate = FormCreate
PixelsPerInch = 96
TextHeight = 13
object Chart1: TChart
Left = 56
Top = 24
Width = 465
Height = 409
BackWall.Brush.Color = clWhite
BackWall.Brush.Style = bsClear
Title.Text.Strings = (
'TChart')
Legend.Visible = False
View3D = False
TabOrder = 0
object LineSeries: TLineSeries
Marks.ArrowLength = 8
Marks.Visible = False
SeriesColor = clBlue
LinePen.Color = clBlue
LinePen.Width = 4
Pointer.InflateMargins = True
Pointer.Style = psCircle
Pointer.Visible = True
XValues.DateTime = False
XValues.Name = 'X'
XValues.Multiplier = 1.000000000000000000
XValues.Order = loAscending
YValues.DateTime = False
YValues.Name = 'Y'
YValues.Multiplier = 1.000000000000000000
YValues.Order = loNone
end
object StairSeries: TFastLineSeries
Marks.ArrowLength = 8
Marks.Transparent = True
Marks.Frame.Visible = False
Marks.Visible = True
SeriesColor = clRed
OnGetMarkText = StairSeriesGetMarkText
LinePen.Color = clRed
LinePen.Style = psDash
LinePen.Width = 2
XValues.DateTime = False
XValues.Name = 'X'
XValues.Multiplier = 1.000000000000000000
XValues.Order = loAscending
YValues.DateTime = False
YValues.Name = 'Y'
YValues.Multiplier = 1.000000000000000000
YValues.Order = loNone
end
end
end
Note: This is a Delphi 7 example that I originally built using Delphi 10.2 and tested it with Delphi 2007. I downgraded the code to Delphi 7.
To use in Delphi 2007 or higher change the code that sets the Axes MinMax to this:
Chart1.Axes.Left.SetMinMax(LeftMinimum, LeftMinimum+12);
Chart1.Axes.Bottom.SetMinMax(BottomMinimum, BottomMinimum+0.75);
The resulting chart should look like this: