vcl-404988-expresscharts-vcl-chart-appearance-customization.md
The Chart control has multiple appearance customization options at different UI element levels – from global settings to individual titles, labels, and series points. You can configure general appearance settings, apply predefined and custom palettes, and handle dedicated events to customize individual visual elements.
Every visual element has a set of general appearance settings accessible through the corresponding Appearance property. This property allows you to change font, margin, padding, fill, and outline settings depending on the visual element type and its purpose in the Chart control.
The list below enumerates Appearance properties accessible through different visual elements at different levels. Different visual elements implement different subsets of options declared in the base TdxChartVisualElementAppearance class.
TdxCustomChartControl.AppearanceProvides access to the Chart control’s appearance settings.TdxChartCrosshairLabels.AppearanceProvides access to crosshair label appearance settings.TdxChartCrosshairLines.AppearanceProvides access to crosshair line appearance settings.TdxChartTitleCollectionItem.AppearanceProvides access to general title appearance settings.
TdxChartCustomLegend.AppearanceProvides access to general legend pane appearance settings.TdxChartVisualElementTitle.AppearanceProvides access to general title appearance settings.
TdxChartCustomDiagram.AppearanceProvides access to diagram appearance settings.
TdxChartSeriesValueLabels.AppearanceProvides access to general appearance settings of series value labels.TdxChartSimpleSeriesCustomView.AppearanceProvides access to Simple View appearance settings.TdxChartAxisValueLabels.AppearanceProvides access to appearance settings of value labels.TdxChartCrosshairAxisLabels.AppearanceProvides access to the general appearance settings of crosshair axis labels.TdxChartCustomAxis.AppearanceProvides access to general axis appearance options.TdxChartXYSeriesAreaView.AppearanceProvides access to Area View appearance settings.TdxChartXYSeriesCustomBarView.AppearanceProvides access to bar appearance settings.TdxChartXYSeriesLineMarkers.AppearanceProvides access to general appearance settings of value markers.TdxChartXYSeriesLineView.AppearanceProvides access to line appearance settings.
The Chart control allows you to apply predefined and custom palettes to XY series and individual points in simple series.
Refer to the following topic for detailed information on all available options: Chart Palettes.
In addition to general appearance settings and palettes, the Chart control has dedicated customization events that allow you to change the appearance of individual visual elements based on certain conditions or events in your application. Any changes made in handlers of these events have higher priority than all other appearance customization options.
The following Chart appearance customization events occur every time the Chart control is about to determine how to draw the corresponding visual element:
TdxChartCustomDiagram.OnGetSeriesPointDrawParametersAllows you to customize the appearance of individual series points.TdxChartCustomDiagram.OnGetValueLabelDrawParametersAllows you to customize series value labels.TdxChartSimpleDiagram.OnGetTotalLabelDrawParametersAllows you to customize individual total labels in the diagram.
Refer to the following topic for detailed information on all available options: Chart Appearance Customization Events.