Question

我需要绘制teechart看起来像图片。如何在德尔福的teechart上绘制红线？

Answer 1

除了行数据TLineSeries之外，添加TFastLineSeries Stairs属性设置为true以创建标记指定数据点的虚线。（结果图表的图像附在答案的末尾）。

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.

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

注意：这是我最初使用Delphi 10.2构建的Delphi 7示例，并使用Delphi 2007对其进行了测试。我将代码降级为Delphi 7.

要在Delphi 2007或更高版本中使用，请将设置Axes MinMax的代码更改为：

    Chart1.Axes.Left.SetMinMax(LeftMinimum,   LeftMinimum+12);
  Chart1.Axes.Bottom.SetMinMax(BottomMinimum, BottomMinimum+0.75);

结果图表应如下所示：

如何在德尔福的teechart上绘制红线

1 个答案: