TdxChartGetSeriesPointDrawParametersEvent Type
The procedural type for series point customization events.
Declaration
TdxChartGetSeriesPointDrawParametersEvent = procedure(Sender: TdxChartCustomDiagram; AArgs: TdxChartGetSeriesPointDrawParametersEventArgs) of object;
Parameters
Name | Type | Description |
---|---|---|
Sender | TdxChartCustomDiagram | The diagram that raised the series point customization event. Cast this parameter value to the TdxChartXYDiagram or TdxChartSimpleDiagram class depending on the actual diagram type to access all public API members. You can call the |
AArgs | TdxChartGetSeriesPointDrawParametersEventArgs | Provides access to draw parameters of the processed series point in the diagram accessible through the You can use |
Remarks
Series Views and their settings define the appearance of all points in the same series. You can handle a series point customization event to change the appearance of individual series points depending on certain conditions.
Accessible Event Parameters
Use the Args
.SeriesPoint property within an event handler to identify the currently processed series point.
The Args
.DrawParameters property provides access to series point appearance settings depending on the parent series type and its active View. To access point appearance settings, you need to cast the Args
.DrawParameters property value to the corresponding TdxChartSeriesPointDrawParameters class descendant:
- TdxChartAreaSeriesPointDrawParameters
- Stores series point draw settings in an Area series View.
- TdxChartLineSeriesPointDrawParameters
- Stores series point draw settings in a Line series View.
- TdxChartBarSeriesPointDrawParameters
- Stores series point draw settings in a Bar series View.
- TdxChartSimpleSeriesPointDrawParameters
- Stores series point draw settings in a simple series View.
Tip
You can call the Args.DrawParameters
.ClassType function to identify the actual series point appearance settings type.
Code Example
The following code example demonstrates a diagram’s OnGetSeriesPointDrawParameters event handler that changes the appearance settings of points with peak values in a Simple Area series:
procedure TMyForm.cdAreaGetSeriesPointDrawParameters(Sender: TdxChartCustomDiagram;
AArgs: TdxChartGetSeriesPointDrawParametersEventArgs);
var
AAreaDrawParameters: TdxChartAreaSeriesPointDrawParameters;
ASeries: TdxChartCustomSeries;
AIndex: Integer;
begin
if AArgs.SeriesPoint.Series.Caption = 'DevAV South' then
begin
if AArgs.DrawParameters.ClassType <> TdxChartAreaSeriesPointDrawParameters then Exit;
AAreaDrawParameters := AArgs.DrawParameters as TdxChartAreaSeriesPointDrawParameters;
AIndex := AArgs.SeriesPoint.Index;
ASeries := AArgs.SeriesPoint.Series;
if ((AIndex = 0) and (ASeries.Points.Values[AIndex] > ASeries.Points.Values[AIndex + 1])) or
((AIndex > 0) and (AIndex < ASeries.Points.Count - 1) and
(ASeries.Points.Values[AIndex] > ASeries.Points.Values[AIndex + 1]) and
(ASeries.Points.Values[AIndex] > ASeries.Points.Values[AIndex - 1])) then
begin
AAreaDrawParameters.MarkerAppearance.FillOptions.Color := TdxAlphaColors.Red;
AAreaDrawParameters.Appearance.BeginUpdate;
AAreaDrawParameters.Appearance.FillOptions.Color := TdxAlphaColors.OrangeRed;
AAreaDrawParameters.Appearance.FillOptions.Mode := TdxFillOptionsMode.Hatch;
AAreaDrawParameters.Appearance.FillOptions.HatchStyle := TdxFillOptionsHatchStyle.ForwardDiagonal;
AAreaDrawParameters.Appearance.FillOptions.Color2 := TdxAlphaColors.Teal;
AAreaDrawParameters.Appearance.StrokeOptions.Color := TdxAlphaColors.Red;
AAreaDrawParameters.Appearance.StrokeOptions.Style := TdxStrokeStyle.Solid;
AAreaDrawParameters.Appearance.EndUpdate;
end;
end;
end;
Direct TdxChartGetSeriesPointDrawParametersEvent Type References
The OnGetSeriesPointDrawParameters event of XY and simple diagrams references the TdxChartGetSeriesPointDrawParametersEvent
procedural type.